Impact of Lavender Flower Powder as a Flavoring Ingredient on Volatile Composition and Quality Characteristics of Gouda-Type Cheese during Ripening

Abstract

This study aimed to formulate a Gouda-type cheese from cow’s milk, flavored with lavender flower powder (0.5 g/L matured milk), ripened for 30 days at 14 °C and 85% relative humidity. Physicochemical, microbiological, and textural characteristics, as well as the volatile composition of the control (CC—cheese without lavender) and lavender cheese (LC), were assessed at 10-day intervals of ripening. Consumers’ perception, acceptance, and purchase intention were only evaluated for ripened cheeses. Moisture and carbohydrate contents, the pH, cohesiveness, indexes of springiness and chewiness decreased during ripening in both CC and LC; however, protein, ash, and sodium chloride contents, titratable acidity, hardness, lactobacilli, streptococci, and volatiles increased. Fat and fat in dry matter contents, respectively, the energy value did not vary with ripening time in LC and increased in CC; gumminess decreased in CC and did not change in LC. Lavender flower powder significantly affected the cheese’s microbiological and sensory characteristics and volatile composition but did not considerably impact physicochemical and textural ones. Populations of lactobacilli and streptococci were substantially higher in LC compared to CC. The volatile profile of LC was dominated by terpene and terpenoids, and that of CC by haloalkanes. Sensory scores were slightly lower for LC than CC, even if it did not considerably affect consumers’ acceptance and purchase intention.

1. Introduction

Gouda is a ripened firm/semi-hard cheese with a body color ranging from near-white or ivory to light yellow or yellow and a firm texture. Its interior has a few to plenty of gas holes uniformly distributed. This type of cheese has a smooth and dry rind, with few openings and splits accepted [1]. It is ordinarily made from pasteurized cow’s milk and acidified with a mesophilic starter culture containing miscellaneous lactic acid bacteria [2]. Gouda cheese generally has an inside diameter of approximately 25.4 cm and a thickness of 16.5 cm. The percentage of water varies from 41.25 to 45.43%, with an average of 43.5% [3].

Furthermore, since several brands of Gouda-type cheese are commercially available, the sensory properties, mainly the cheese flavor, are the key factors affecting consumers’ acceptance and are decisive for purchase intention [4,5]. Thus, dairy manufacturers have started producing differentiated cheeses by incorporating some atypical ingredients, such as lavender [6], cumin [7], red chili pepper [8], fenugreek [9], mustard [10], and garlic [10]. However, despite the potential appeal of these cheeses to consumers, there needs to be more knowledge regarding the effects of adding these flavoring ingredients on the development of texture and flavor in ripened cheese [6].

It is well known that microorganisms, especially those in the starter culture, play an essential role in cheese making; the enzymes produced by them break down cheese constituents such as lipids, proteins, and, to a lesser extent, carbohydrates, improving the product texture and flavor during ripening [11]. The starter culture used in Gouda-type cheese manufacturing includes Lactococcus, Leuconostoc, Lactobacillus, and Streptococcus strains [12]. Members of the Leuconostoc genus and lactococcal variant Lactococcus lactis subsp. lactis biovar. diacetylactis ferment milk citrate into various compounds, the most significant being carbon dioxide (necessary for eye formation in Gouda cheese) and the diacetyl and acetic acid flavors [13].

The antimicrobial properties of some spices/herbs used as ingredients are widely known, and, thus, their possible effects on starter organisms in cheese. On the other hand, the microbiome of these flavoring ingredients also affects the starter culture during ripening, and hence the development of the cheese’s texture and flavor [11]. However, to our knowledge, work has yet to be published regarding the impact of lavender flower powder on the Gouda-type cheese’s ripening process and implicitly on its properties. Therefore, this study proposes a manufacturing process for a Gouda-type cheese flavored by adding lavender flower powder into matured milk to evaluate the effect of lavender flower powder and the ripening time on the cheese’s volatile compounds and the physicochemical, textural, and microbiological characteristics.

2. Materials and Methods

Raw milk (3.8% fat, 3.4% protein, 4.5% lactose, 87.5% moisture, and a pH of 6.5) from Bălțată Românească cattle was used to manufacture the Gouda-type cheeses (LC—with lavender flower powder and CC—without the flavoring ingredient). Cow’s milk was received (as a donation) from a milk farm (P.F.A. Socaci L. Maria) in Chirileu, Mureș County, Romania, with a herd of 30 cows (1–6 lactation cycles). Cows were kept in free stabulation during the daytime to graze on green pastures. As additional roughage, they were fed with a mixture of alfalfa, hay, orchard grass, and silage or a blend of corn, wheat, sunflower, and barley flour.

Lavender (dried bunches of Lavandula angustifolia Mill.) was purchased from a lavender farm (Lavanda Lola) in Bonțida, Cluj County, Romania. The flavoring ingredient, lavender flower powder, was prepared by grinding lavender flowers (manually detached from stems and separated from impurities) to a fine powder using a mortar grinder (RM 200; Retsch GmbH, Haan, Germany); the powder thus obtained was then sealed into a glass jar with a lid and kept in a cool, dry place until use.

2.1. Manufacturing of Gouda-Type Cheese

Gouda-type cheese was made as described in our previous paper [6]. An average quantity of 3.85 kg CC and 3.95 kg LC was obtained from processing 30 L cow’s milk. The flowchart in Figure 1 shows the manufacturing process steps for LC (see Figure 2a); CC (see Figure 2b) was manufactured similarly but without lavender flower powder. Both treated (LC) and untreated (CC) cheeses were produced in two batches. The amount of lavender flower powder (15 g) added into matured milk (30 L) to flavor the cheese was selected from a series of tested concentrations (30, 25, 20, and 15 g lavender powder per 30 L of milk) based on a sensory evaluation of cheese (performed using an internal, trained panel of 6 assessors).

All analyses were performed both on the lavender (LC) and control cheese (CC) at ten (T1), twenty (T2), and thirty days (T3) of ripening, as mentioned in Section 2.2, Section 2.3, Section 2.4, Section 2.5 and Section 2.6. In addition, consumers’ perception, acceptance, and purchase intention were also determined for ripened LC and CC, as described in Section 2.7.

2.2. Proximate Composition Analysis of Cheese and Calculation of Total Carbohydrate Content, Fat in Dry Matter Content, and Energy Value

Moisture content was determined by drying the sample to a constant weight in an electric oven (Digitheat; J.P. Selecta S.A., Barcelona, Spain), following instructions provided by ISO 5534:2004|IDF 4:2004 [14].

Determination of the nitrogen content and calculation of crude protein was carried out as described in ISO 8968-1:2014|IDF 20-1:2014 [15] using the Kjeldahl method. It involved acid digestion of the sample (DK6 Heating Digester; VELP Scientifica SRL, Usmate Velate, Italy), followed by alkalization and steam distillation of the acid digest (UDK 129 Distillation Unit; VELP Scientifica S.R.L., Usmate Velate, Italy), and finally by quantification of the trapped ammonia through titration. The protein content in cheese was estimated by multiplying the total nitrogen by 6.25, a nitrogen-to-protein conversion factor.

Fat content was determined directly using the Van Gulik method from ISO 3433:2008|IDF 222:2008 [16], while fat in dry matter (FDM) content was calculated by the following Formula (1):

$$FDM \left(\%\right)=\frac{F}{DM}\times 100$$

(1)

where $F$ is the fat content (%) of the cheese, and $DM$ is the dry matter content (%) of the cheese (computed by subtracting moisture content (%) from 100).

Ash content was determined by incineration of the sample in a muffle furnace (L3/11/B170; Nabertherm GmbH, Bremen, Germany), as detailed by Nagy et al. [17]. First, approximately 1.0 g of grated cheese was weighed to the nearest 1 mg (ABJ-220-4NM; Kern & Sohn GmbH, Balingen, Germany) into a porcelain crucible, and it was then heated at 600 °C for 12 h in the muffle furnace, cooled in a desiccator, and weighed again. Finally, the percentage of ash content was calculated with the following Formula (2):

$$Ash \left(\%\right)=\frac{w_a}{w_s}\times 100$$

(2)

where $w_a$ is the weight (g) of ash, and $w_s$ is the weight (g) of the sample.

All samples were analyzed in triplicate, and results were expressed in percentages.

Total carbohydrate content (%) was calculated from Formula (3) used by Nagy et al. [17]:

$$Total carbohydrate \left(\%\right)=100-\left(\% \mathrm{moisture}+\% \mathrm{protein}+\% \mathrm{fat}+\% \mathrm{ash}\right)$$

(3)

The energy value of cheese was calculated according to Nagy et al. [17] using the following Formula (4):

$$Energy value \left(\mathrm{kcal}/100 \mathrm{g}\right)=4\times \left(\mathrm{g} protein+\mathrm{g} carbohydrate\right)+9\times \left(\mathrm{g} fat\right)$$

(4)

2.3. Determination of Sodium Chloride Content, pH, and Titratable Acidity of the Cheese

Sodium chloride content, expressed as a percentage, was determined following the potentiometric titration method specified in ISO 5943:2006|IDF 88:2006 [18]. The pH measurement of cheese was performed with a portable pH meter (HI 99161; Hanna Instruments, Limena, Italy). Titratable acidity, expressed in Thörner degrees (°T), was determined using the titrimetric method from STAS 6353-85 [19], a Romanian standard. All samples were analyzed in triplicate.

2.4. Texture Profile Analysis of Cheese

This analysis included measurement of the hardness (N), cohesiveness, springiness index, gumminess (N), and chewiness index (N) of cheese sample using a texture analyzer (CT3; Brookfield Engineering Laboratories Inc., Middleboro, MA, USA), according to the method described by Ong et al. [20]. Samples, in 1.5 cm cubes, were taken from the central part of the cheese using a knife and kept at 20 °C for 1 h in a closed container (to prevent moisture loss) until analysis. The test consisted of sample deformation to 50% of its height (7.5 mm), at a speed of 2 mm/s, with a TA25/1000 cylindrical probe attached to a 10 kg compression cell. Measurements were carried out on each cheese batch in triplicate (six in total for each treatment) using the TexturePro CT software.

2.5. Microbiological Analysis of Cheese

A portion of 5.0 g grated cheese was aseptically weighed into a sterile stomacher bag and homogenized in 45 mL of 0.85% (w/v) sodium chloride solution (27810.295P; VWR Chemicals, Leuven, Belgium) for 1 min using a laboratory blender (MiniMix 100 P CC; Interscience, Saint-Nom-la-Bretèche, France), as described by Socaciu et al. [21]. Seven ten-fold serial dilutions (10⁻², 10⁻³, 10⁻⁴, 10⁻⁵, 10⁻⁶, 10⁻⁷, and 10⁻⁸) were prepared from this stock solution (10⁻¹).

Lactobacilli and streptococci counts were determined in cheese according to the method described by the ISO 7889:2003|IDF 117:2003 standard [22] using MRS broth (110611; Merck KGaA, Darmstadt, Germany) and M17 agar (CM0785; Oxoid Ltd., Basingstoke, England), respectively. Enumeration of lactobacilli and streptococci colonies was performed after incubating inoculated plates at 37 °C for 48 h under anaerobic conditions. All samples were analyzed in triplicate, and results were reported as log cfu/g. In addition, the total lactic acid bacteria count (log cfu/g) was calculated as the sum of the lactobacilli and streptococci counts.

2.6. Analysis of Volatile Compounds in Cheese

This was performed following the method described by Cozzolino et al. [23], with minor modifications. Into a 20-mL SPME crimp neck vial (22.5 × 75.5 mm; VWR International s.r.l., Milano, Italy), approximately 3.5 g of grated cheese was weighed to the nearest 0.1 mg using an analytical balance (E42; Gibertini Elettronica S.R.L., Milano, Italy); 3 mL aqueous solution of hydrochloric acid (0.03% 6 M HCl; Merk KGaA, Darmstadt, Germany) was added to cheese sample and mixed, followed by 5 µL methanolic solution of methyl nonanoate (1175 μg/mL; Sigma-Aldrich Chemie GmbH, Steinheim, Switzerland), used as an internal standard. First, the vial’s content was stirred and then kept for 30 min at 40 °C in the autosampler thermostat (HT2850T autosampler; HTA S.r.l., Brescia, Italy) to reach equilibrium. Next, an SPME fiber (50/30 µm DVB/CAR/PDMS; Supelco Inc., Bellefonte, PA, USA) was inserted into the vial’s septum and exposed to the sample headspace at 40 °C for 30 min to adsorb the volatile compounds. Before its first use, the fiber was conditioned at 270 °C for 60 min, according to the manufacturer’s recommendations. After sampling, it was retracted and automatically injected into the gas chromatograph injection port of a GCMS-QP2010 Plus instrument (Shimadzu Corp., Kyoto, Japan) equipped with an Rtx-Wax capillary column (Crossbond^® Carbowax^® polyethylene glycol; 30 mL × 0.25 mm ID × 0.25 μm film thickness; Restek Corp., Bellefonte, PA, USA), where volatile compounds were desorbed for 10 min in spitless mode. Helium was the carrier gas at 1 mL/min constant flow. The injector temperature was set to 250 °C, and the oven one was programmed initially at 40 °C and held at this temperature for 2 min. Subsequently, it was increased by 5 °C/min up to 65 °C and kept at 65 °C for 2 min, and then by 10 °C/min up to 240 °C and held at 240 °C for 9 min. Interface and ion source temperatures were set to 210 and 230 °C, respectively, and the filament voltage to 70 eV (electronic impact). Chromatographic analysis was carried out in triplicate for each cheese sample. Volatile compounds were identified by comparing their recorded mass spectra with those found in the NIST27 and NIST147 libraries. The relative content of each volatile compound was calculated as the ratio of its total ion current (TIC) area to the TIC area of the internal standard using the following Formula (5):

$$Conc A \left(\mu \mathrm{g}/\mathrm{kg} cheese\right)=\left(\frac{Peak are{a}_A}{Peak are{a}_{IS}}\times \frac{a_{IS}}{w_c}\right)\times 1000$$

(5)

where $Conc A$ is the analyte concentration, $Peak are{a}_A$ is the analyte peak area, $Peak are{a}_{IS}$ is the internal standard peak area, $a_{IS}$ is the amount of internal standard added to the sample (µg), and $w_c$ is the cheese weight (g).

2.7. Sensory Analysis of Cheese and Determination of Consumers’ Acceptance and Purchase Intention

Cheese samples were assessed for appearance and color, consistency and texture, odor and taste, aftertaste, and overall liking using a nine-point hedonic scale (1—dislike extremely; 2—dislike very much; 3—dislike moderately; 4—dislike slightly; 5—neither like nor dislike; 6—like slightly; 7—like moderately; 8—like very much; 9—like extremely). They were coded with 3-digit random numbers and presented to panelists (50 women and 30 men aged 20–43 years) on white ceramic plates. The sensory attributes of CC and LC were rated at 20 °C (air conditioning) under white light. Panelists were asked not to eat, drink, or smoke for at least 1 h before the evaluation session (conducted in individual booths).

Consumers’ purchase intention was rated on a 5-point scale (1—definitely will buy; 2—probably will buy; 3—might or might not buy; 4—probably will not buy; 5—definitely will not buy) [24]. The acceptance rate (AR) of each cheese type was calculated as described previously by dos Reis Santos et al. [25] using the following Formula (6):

$$AR \left(\%\right)=\frac{X}{N}\times 100$$

(6)

where $X$ is the mean sensory score of the cheese, and $N$ is the maximum sensory score given by panelists to the cheese.

2.8. Statistical Analysis

The Minitab statistical software (version 19.1.1; LEAD Technologies, Inc., Charlotte, NC, USA) was used for data analysis. The effects of the lavender flower powder and ripening time on the Gouda-type cheese’s characteristics and volatile compounds were analyzed by one-way ANOVA with a post-hoc Tukey’s test at a 95% confidence level (p < 0.05). In addition, hierarchical cluster analysis (HCA) was performed using the MetaboAnalyst software (version 5.0; Xia Lab at McGill University, Montreal, QC, Canada).

3. Results and Discussion

3.1. Nutritional Properties of Gouda-Type Cheese

Changes in the proximate composition, sodium chloride content, pH, titratable acidity, and energy value of the control (CC) and lavender Gouda-type cheese (LC) at 10-day intervals during 30 days of ripening are shown in

Table 1. Proximate chemical composition, sodium chloride content, pH, titratable acidity, and energy value of control and lavender Gouda-type cheese at different ripening times (T1, T2, and T3).

Parameter/Energy Value	Control Cheese			Lavender Cheese
	T1	T2	T3	T1	T2	T3
Moisture (%)	36.84 ± 0.270aA	35.80 ± 0.060abA	34.97 ± 0.064bA	37.87 ± 0.282aA	36.57 ± 0.630abA	35.48 ± 0.165bA
Protein (%)	21.13 ± 0.191cA	22.11 ± 0.014bA	23.17 ± 0.212aB	21.55 ± 0.078cA	22.39 ± 0.134bA	24.90 ± 0.113aA
Fat (%)	28.25 ± 0.354cA	29.50 ± 0.0bA	30.75 ± 0.354aA	29.25 ± 0.354aA	29.25 ± 0.354aA	29.75 ± 0.354aA
Fat in dry matter (%)	44.73 ± 0.057cB	45.95 ± 0.042bA	47.29 ± 0.495aA	47.08 ± 0.354aA	46.11 ± 0.099aA	46.11 ± 0.431aA
Ash (%)	4.28 ± 0.014bA	4.49 ± 0.156bA	5.45 ± 0.014aA	4.25 ± 0.007bA	4.31 ± 0.035bA	5.06 ± 0.028aB
Total carbohydrate (%)	9.51 ± 0.700aA	8.10 ± 0.205aA	5.66 ± 0.488bA	7.09 ± 0.0aB	7.50 ± 0.177aA	4.82 ± 0.106bA
Sodium chloride (%)	2.37 ± 0.028cA	2.60 ± 0.021bB	2.71 ± 0.007aB	2.26 ± 0.028cA	2.91 ± 0.028bA	3.28 ± 0.071aA
pH	4.87 ± 0.014aB	4.73 ± 0.007bA	4.60 ± 0.0cA	4.99 ± 0.007aA	4.83 ± 0.092abA	4.65 ± 0.042bA
Titratable acidity (°T)	85.2 ± 0.566cA	90.6 ± 0.849bA	95.0 ± 0.283aA	79.8 ± 0.283cB	83.8 ± 0.283bB	92.0 ± 0.0aB
Energy value (kcal/100 g)	377 ± 4.950bA	387 ± 0.707abA	393 ± 2.121aA	378 ± 2.828aA	383 ± 4.243aA	387 ± 2.121aA

T1—10 days of ripening; T2—20 days of ripening; T3—30 days of ripening. Data are expressed as mean ± standard deviation values of all measurements. Different lowercase letters in the same row indicate significant differences between ripening times (p < 0.05, Tukey’s test), and different uppercase letters show significant differences between cheeses (p < 0.05).

. Moisture content significantly decreased with ripening time, from 36.84 to 34.97% in CC and from 37.87 to 35.48% in LC, causing an increase in protein (from 21.13 to 23.17% in CC; from 21.55 to 24.90% in LC), ash (from 4.28 to 5.45% in CC; from 4.25 to 5.06% in LC), and sodium chloride contents (from 4.28 to 5.45% in CC; from 4.25 to 5.06% in LC). On the other hand, the fat content of the Gouda-type cheese increased in CC (from 28.25 to 30.75%) while this matured but did not vary significantly in LC (from 29.25 to 29.75%); the same trends were noticed for the fat in dry matter content and energy value of CC and LC, respectively (see Table 1). Regarding carbohydrates, their content significantly declined in both CC and LC during ripening, as lactic acid bacteria consumed them, causing a fall in pH (from 4.87 to 4.60 in CC; from 4.99 to 4.65 in LC) and an increase in titratable acidity (from 85.2 to 95.0 °T in CC; from 79.8 to 92.0 °T in LC). It is well known that lactic acid bacteria use carbohydrates as a primary carbon source [26], lactic acid being the major end-product of milk lactose fermentation [27]. These results are corroborated by microbiological findings showing the multiplication of lactic acid bacteria in CC and LC with ripening. Furthermore, at the ripening period’s end, protein and sodium chloride contents in LC were significantly higher than in CC, while the ash content and titratable acidity were lower. Nevertheless, both CC and LC met the quality requirements in the Codex standard for Gouda, namely CXS 266-1966 [1].

3.2. Textural Properties of Gouda-Type Cheese

Instrumental measurements of texture attributes in CC and LC are presented in

Table 2. Texture attribute values for control and lavender Gouda-type cheese at different ripening times (T1, T2, and T3).

Texture Attribute	Control Cheese			Lavender Cheese
	T1	T2	T3	T1	T2	T3
Hardness (N)	35.43 ± 2.456bA	36.52 ± 5.547bA	53.07 ± 10.105aA	24.72 ± 3.534bB	40.56 ± 10.605aA	41.51 ± 9.777aA
Cohesiveness	0.46 ± 0.066aA	0.37 ± 0.047bA	0.24 ± 0.028cA	0.44 ± 0.061aA	0.29 ± 0.036bB	0.24 ± 0.030bA
Springiness index	0.83 ± 0.026aA	0.79 ± 0.061aA	0.54 ± 0.076bA	0.82 ± 0.088aA	0.80 ± 0.048aA	0.68 ± 0.019bA
Gumminess (N)	16.09 ± 2.530aA	19.90 ± 6.244aA	8.94 ± 2.153bA	10.72 ± 0.987aB	11.72 ± 2.580aB	10.17 ± 3.366aA
Chewiness index (N)	13.35 ± 2.229aA	15.71 ± 5.299aA	4.90 ± 1.587bA	8.57 ± 1.121aB	9.43 ± 2.914aB	6.96 ± 1.060bA

T1—10 days of ripening; T2—20 days of ripening; T3—30 days of ripening. Data are expressed as mean ± standard deviation values of all measurements. Different lowercase letters in the same row indicate significant differences between ripening times (p < 0.05, Tukey’s test), and different uppercase letters show significant differences between cheeses (p < 0.05).

. Consistent with the findings of Kanawjia et al. [28] on Gouda cheese, the hardness, springiness index, gumminess, and chewiness decreased in CC and LC during ripening, except for gumminess in LC, which did not change significantly. However, no significant differences between the texture attribute values of CC and LC were found at the final stage of ripening.

Hardness indicates the maximum force required to compress cheese between the molar teeth. In CC, it significantly increased from a value of 35.43 N on day 10 of ripening to 53.07 N on day 30, and in LC, it raised from 24.72 to 41.51 N, most likely due to a loss of moisture.

Cohesiveness, also known as consistency, shows the strength of the internal bonds making up a cheese’s body. Surprisingly, and contrary to the findings of Kanawjia et al. [28], we noticed a downward trend with ripening time for both CC (from 0.46 to 0.24) and LC (from 0.44 to 0.24). Nevertheless, Ivanov et al. [29] reported changes in the cohesiveness of Kashkaval cheese during ripening, like those we observed, being attributed to proteolysis.

The springiness index is a texture attribute that shows the viscoelastic properties of cheese and ranges from 0 (completely viscous material) to 1 (completely elastic material). As can be seen in Table 2 below, it significantly decreased during ripening, from 0.73 to 0.54 in CC and from 0.82 to 0.68 in LC. Our results are in accordance with those reported by Zheng et al. [30] and reveal that the low moisture content in Gouda-type cheese is associated with high firmness but low springiness and cohesiveness.

Gumminess is the energy required to disintegrate cheese into a state ready for swallowing. Its level significantly decreased in CC as it ripened (from 16.09 to 8.94 N), as in the study of Pinto et al. [31], while in LC (from 10.72 to 10.17 N), it did not vary considerably.

Chewiness indicates the energy required to chew cheese to a state whereby it is ready for swallowing. The chewiness index is estimated as hardness × cohesiveness × springiness index. It decreased with ripening time, from 13.35 N in CC and 8.57 N in LC to 8.57 and 6.96 N, respectively. In another study, Pinto et al. [31] also noticed a decreasing change in cheese chewiness during ripening.

3.3. Microbiological Properties of Gouda-Type Cheese

The starter culture used for Gouda-type cheese-making contains a mixture of thermophilic and mesophilic bacteria such as Lactococcus lactis ssp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis, Lactobacillus helveticus, Lactobacillus paracasei, Leuconostoc species, and Streptococcus thermophilus. Therefore, the effect of lavender flower powder on lactic acid bacteria growth in Gouda-type cheese was evaluated by determining the lactobacilli and streptococci count, also, the total lactic acid bacteria count (see

Table 3. Counts of lactobacilli, streptococci, and total lactic acid bacteria in control and lavender Gouda-type cheese at different ripening times (T1, T2, and T3).

Parameter	Control Cheese			Lavender Cheese
	T1	T2	T3	T1	T2	T3
Lactobacilli count	9.5 ± 0.007cB	9.7 ± 0.009bB	9.8 ± 0.004aB	9.7 ± 0.005cA	9.8 ± 0.004bA	9.9 ± 0.006aA
Streptococci count	8.7 ± 0.011cB	9.2 ± 0.011bB	9.3 ± 0.016aB	9.0 ± 0.024cA	9.5 ± 0.012bA	9.6 ± 0.013aA
Total lactic acid bacteria count	18.2 ± 0.004cB	18.9 ± 0.002bB	19.1 ± 0.020aB	18.7 ± 0.019cA	19.3 ± 0.008bA	19.5 ± 0.020aA

T1—10 days of ripening; T2—20 days of ripening; T3—30 days of ripening. Data are expressed as mean ± standard deviation values of all enumerations. Different lowercase letters in the same row indicate significant differences between ripening times (p < 0.05, Tukey’s test), and different uppercase letters show significant differences between cheeses (p < 0.05).

).

The antibacterial effect of lavender against Escherichia coli, responsible for early cheese blowing, and Clostridium tyrobutiricum, responsible for late cheese blowing, was reported by Librán et al. [32] in a previous study. Therefore, we assumed that lavender flower powder, used as a flavoring ingredient in our Gouda-type cheese, could inhibit the growth of starter culture microorganisms during ripening. Nevertheless, contrary to our expectation, it stimulated the development of lactic acid bacteria since the counts of lactobacilli, streptococci, and total lactic acid bacteria were significantly higher in LC at all ripening times.

However, in line with the study of Öztürk et al. [33], the flavoring ingredient reported herein caused a significant increase in the lactobacilli and streptococci count in CC and LC with ripening time (in CC, from 9.5 to 9.8 log cfu/g, and in LC, from 9.7 to 9.9 log cfu/g for lactobacilli count; in CC, from 8.7 to 9.3 log cfu/g, and in LC, from 9.0 to 9.6 log cfu/g for streptococci count; in CC, from 18.2 to 19.1 log cfu/g, and in LC, from 18.7 to 19.5 log cfu/g for total lactic acid bacteria count). These results also explain the below-discussed accumulation of volatile compounds during cheese ripening in both CC and LC.

3.4. Volatile Compounds in Gouda-Type Cheese

Results of headspace-SPME-GC/MS analysis for quantifying volatile compounds in the Gouda-type cheeses are shown in Table 4. Thirty-seven volatile compounds were detected in CC at T1, classified under six different identified compounds: haloalkane (32.0%—one compound) was the most dominant group, followed by alcohols (23.2%—nine compounds), carboxylic acids (15.4%—six compounds), cyanoalkanes (8.3%—one compound), esters (8.1%—six compounds), and ketones (5.9%—three compounds). Moreover, five compounds were classified within the chemical class of terpenes and terpenoids (3.3%), three in aldehydes (2.2%), two in aromatic hydrocarbons (1.2%), and one in pyridines (0.4%). To better visualize the similarities and differences between cheese samples at different ripening stages regarding the volatile composition, hierarchical cluster analysis (HCA) was run (see Figure 3).

Control cheese. Chloroform (32.0%; No. 5 in Table 4) was the most dominant compound present in CC at T1, followed by acetonitrile (8.3%; No. 4), isopropanol (6.6%; No. 2), 1-butanol (6.0%; No. 12), isoamyl alcohol (5.8%; No. 19), caproic acid (5.6%; No. 59), acetoin (5.6%; No. 28), and methyl hexanoate (4.2%; No. 17); of these, chloroform, toluene, acetonitrile, and isopropanol were found in the Gouda-type cheese for the first time. Previous findings have revealed the presence of chloroform in semi-hard goat cheese (Kınık et al. [34]), chloroform and toluene in some varieties of Turkish cheese (Hayaloglu and Karabulut [35]), and acetonitrile and isopropanol in Manchego cheese (Gómez-Ruiz et al. [36]). It is well known that chloroform and acetonitrile derive from the breakdown of milk carotene [35,36]. Chloroform may also derive from the chlorine-containing cleaning products used for cheese-processing equipment disinfection [37]. Alcohols (23.2%), the second most dominant class in CC at T1, would be the consequence of the abovementioned compounds’ abundance, together with the presence of optical (0.9%) and meso isomers (2.4%) of 2,3-butanediol. Meanwhile, 1-butanol, isoamyl alcohol, and 2,3-butanediol were also discovered in Gouda-type cheese by Van Leuven et al. [38] and Van Hoorde et al. [39]. Some authors reported that they arise from butanal (resulting from fatty acid or amino acid metabolism), leucine, and acetoin, respectively [36,40,41]. Carboxylic acids (15.4%), the third class in abundance in CC at T1, were represented by acetic acid (2.8%), butyric acid (2.4%), and caproic acid (10.2%), all previously reported in Gouda-type cheese by other studies [38,39,42,43,44,45,46]. They can originate from milk fat lipolysis or lactose and lactic acid fermentation [35]. Cyanoalkanes (8.3%), esters (8.1%), ketones (5.9%), terpene and terpenoids (3.3%), aldehydes (2.2%), aromatic hydrocarbons (1.2%), and pyridines (0.4%) were the subsequent classes of volatile compounds grouped in CC at T1. Acetoin, listed among the significant volatile constituents in CC at T1, is a volatile compound from the ketone class. It was identified as a derivative of milk citrates [36] and, therefore, detected in Gouda-type cheese by other researchers [38,45,46]. Methyl hexanoate (4.2%), from the ester class, another notable volatile compound in CC at T1, was also reported in some commercial Gouda cheeses [2]. Its occurrence is probably related to the esterase activity of lactic acid bacteria [36]. As for aldehydes in cheese, they are produced by the catabolism of fatty acids or amino acids via decarboxylation or deamination [35,47]; only benzaldehyde (1.5%), hexanal (0.2%), and heptanal (0.5%) were detected in CC at T1, but it seems that they are commonly present in Gouda-type cheeses [38,39,45]. Both hexanal and heptanal disappeared during ripening; heptanal was no longer detected in CC on the 20th day of maturation and hexanal on the 30th—hence the lower number of volatile compounds found in CC at T2 (thirty-six) and CC at T3 (thirty-five). o-Cymene (1.7%), β-ocimene, trans-β-ocimene (0.6%), ɣ-terpinene (0.2%), and linalool (0.3%), volatile compounds of the terpene and terpenoid class, were also present in CC at T1; since this is the first time that they have been detected in a Gouda-type cheese, they most likely arise from animal feed, considering that the cows had pasture access in the afternoon and evening.

Lavender cheese. The volatile profile of LC at T1 (Table 4), however, was dominated by terpenes and terpenoids (Te&Ts; 42.3%), followed by alcohols (Alc; 15.5%), haloalkanes (HoAlka; 13.3%), carboxylic acids (CA; 11.6%), esters (Es; 7.8%), ketones (Ket; 4%), cyanoalkanes (CyAlka; 3.5%), aldehydes (Ald; 1.6%), aromatic hydrocarbons (AH; 0.2%), and pyridines (Pyr; 0.1%). Sixty-two volatile compounds were detected in this sample, including 12 alcohols, 3 aldehydes, 1 aromatic hydrocarbon, 5 carboxylic acids, 1 cyanoalkane, 10 esters, 1 haloalkane, 4 ketones, 1 pyridine, and 19 compounds from the terpene and terpenoid class, with three more alcohols than in CC at T1 (3-octanol; 2-ethyl-1-hexanol; 2,6-dimethyl-3,7-octadien-2,6-diol), 1 aldehyde (phenylacetaldehyde), 5 esters (an isomer of ethyl butyrate; isoamyl acetate; isoamyl butyrate; 1-octenyl acetate; hexyl butyrate), 1 ketone (3-octanone), and 15 compounds of the terpene and terpenoid class (β-myrcene; 1,8-cineole; 3 isomers of linalool oxide; trans-2-pinanol; linalyl acetate; camphor; linalyl isobutyrate; 4-terpineol; lavandulyl acetate; α-terpineol; borneol; cis-geranyl acetate; caryophyllene oxide). Moreover, isobutyric acid (CA) was identified along with linalyl isobutyrate (Te&Ts), methyl decanoate (Es) with 4-terpineol (Te&Ts), and β-ocimene (Te&Ts) with 3-octanone (Ket). Different from CC at T1, linalool (14.8%; Te&Ts; No. 45 in Table 4) was the main volatile compound in LC at T1, followed by chloroform (13.3%; HoAlka; No. 5) and linalyl isobutyrate (13.1%; Te&Ts; No. 47), and then by caproic acid (4.9%; CA; No. 59), an isomer of trans-linalool oxide (3.9%; Te&Ts; No. 36), 1-hexanol (3.8%; Alc; No. 31), isopropanol (3.7%; Alc; No. 2), acetonitrile (3.5%; CyAlka; No. 4), and 1-butanol (3.1%; Alc; No. 12). The number of volatile constituents in LC did not change with ripening time, but their amount increased from 16,366.71 µg/kg cheese at T1 to 29,619.78 µg/kg cheese at T2 and decreased to 19,695.86 µg/kg cheese at T3. As for CC, the total amount of volatile compounds increased during ripening from 3337.08 µg/kg cheese at T1 to 10,392.16 µg/kg cheese at T2 and further to 14,743.17 µg/kg cheese at T3. The content of total volatile compounds in the Gouda-type cheese was 79.6% higher in LC than in CC at T1, with 64.9% at T2 and 25.1% at T3. As can be noticed in Figure 3, the concentration of volatile compounds either decreased with ripening time, varied in a ˄-pattern, or remained unchanged (cluster 1); in other cases, it increased (cluster 2).

Table 4. Volatile compound concentrations in control and lavender Gouda-type cheese at different ripening times (T1, T2, and T3).

Crt.No.	Volatile Compound	MSS (%)	Odor Descriptor	Reference	CC	Control Cheese			Lavender Cheese
						µg/kg Cheese
						T1	T2	T3	T1	T2	T3
1	Methyl acetate	96	Fruity, solvent, blackcurrant-like	[48]	Es	38.56 ± 4.199bB	67.26 ± 2.948bB	111.20 ± 26.935aA	53.50 ± 1.607bA	115.42 ± 25.312aA	61.89 ± 5.974bB
2	Isopropanol	97	Sharp musty	[49]	Alc	221.75 ± 46.558cB	722.34 ± 89.846bB	1155.17 ± 222.182aA	599.38 ± 75.037bA	1047.99 ± 120.237aA	590.10 ± 7.424bB
3	Methyl butyrate	96	Fruity, apple-like	[50]	Es	54.21 ± 11.983bB	114.20 ± 17.312aB	153.96 ± 31.418aA	180.06 ± 25.014aA	222.23 ± 34.620aA	170.39 ± 1.721aA
4	Acetonitrile	98	-	-	CyAlka	275.86 ± 51.660cB	1083.19 ± 169.607bA	1636.99 ± 279.534aA	575.97 ± 89.883cA	1495.49 ± 197.115aA	1022.22 ± 52.569bB
5	Chloroform	77	Ether-like	[49]	HoAlka	1068.81 ± 206.553cB	3527.63 ± 402.152bA	5590.37 ± 1139.680aA	2176.24 ± 339.353bA	4329.89 ± 565.593aA	4329.89 ± 565.593aA
6	Toluene	94	Nutty, bitter, almonds, paint; fruity	[51,52]	AH	23.03 ± 3.945b	51.99 ± 9.667abA	65.66 ± 18.515aA	n.d.	68.95 ± 22.883aA	41.11 ± 5.903aA
7	Ethyl butyrate (isomer)	95	Fruity, pineapple, acetone, caramel	[48]	Es	n.d.	n.d.	n.d.	39.08 ± 2.587a	50.16 ± 15.106a	28.71 ± 12.886a
8	Butyl acetate	94	Fruity	[49]	Es	15.34 ± 3.106aB	25.07 ± 3.967aA	23.29 ± 5.877aA	27.71 ± 2.459aA	22.75 ± 2.323bA	13.80 ± 0.133cB
9	Hexanal	95	Cut grass	[53]	Ald	16.51 ± 5.051aA	6.68 ± 2.494bA	n.d.	31.52 ± 20.601aA	6.86 ± 2.523aA	19.44 ± 0.720a
10	Isobutanol	91	Choking alcohol	[49]	Alc	6.31 ± 1.424bB	24.40 ± 3.487aB	28.14 ± 8.926aA	12.67 ± 3.009cA	34.31 ± 1.756aA	20.10 ± 3.050bA
11	Isoamyl acetate	97	Banana, chewing gum	[48]	Es	n.d.	n.d.	n.d.	n.d.	62.98 ± 10.744a	52.95 ± 4.624a
12	1-Butanol	97	Medicinal, fruity	[51]	Alc	201.21 ± 41.648cB	640.06 ± 83.138bA	950.89 ± 166.505aA	505.86 ± 71.458aA	638.14 ± 80.605aA	319.35 ± 28.604bB
13	β-Myrcene	93	Balsamic, spice	[54]	Te&Ts	n.d.	n.d.	n.d.	29.92 ± 9.055b	62.30 ± 6.066a	38.28 ± 2.828b
14	Pyridine	92	-	-	Pyr	12.38 ± 3.015bA	50.35 ± 9.850aA	63.41 ± 11.766aA	21.12 ± 6.264aA	21.45 ± 2.673aB	10.31 ± 1.399bB
15	2-Heptanone	88	Fruity	[52]	Ket	6.17 ± 1.257cA	13.62 ± 2.483bB	23.78 ± 1.680aA	10.71 ± 2.732bA	30.92 ± 3.245aA	27.73 ± 2.546aA
16	Heptanal	80	Sour milk/dairy	[52]	Ald	5.94 ± 1.317	n.d.	n.d.	n.d.	n.d.	n.d.
17	Methyl hexanoate	96	Fruity, ester-like	[50]	Es	141.11 ± 25.302bB	288.30 ± 40.965aB	321.42 ± 53.508aA	428.97 ± 58.989aA	496.81 ± 69.633aA	279.30 ± 29.445bA
18	1,8-Cineole	97	Floral, minty, fruity	[54]	Te&Ts	n.d.	n.d.	n.d.	370.96 ± 56.128b	678.05 ± 61.261a	356.96 ± 17.757b
19	Isoamyl alcohol	97	Banana	[55]	Alc	194.44 ± 43.626bB	750.88 ± 94.873aB	831.51 ± 172.253aA	433.41 ± 95.289cA	1284.59 ± 151.738aA	758.69 ± 54.400bA
20	Ethyl butyrate (isomer)	96	Pineapple-like	[49]	Es	8.62 ± 2.144bB	14.59 ± 2.407bB	29.48 ± 7.633aA	79.59 ± 8.303aA	74.89 ± 2.553aA	54.02 ± 9.024bB
21	trans-β-Ocimene	82	Mushroom-like	[56]	Te&Ts	21.33 ± 4.752cA	50.26 ± 4.803bB	66.13 ± 7.807aB	97.95 ± 13.079bB	158.27 ± 8.496aA	90.65 ± 9.332bA
22	ɣ-Terpinene	83	Unpleasant	[57]	Te&Ts	5.57 ± 0.261bB	13.84 ± 1.000aB	14.45 ± 1.618aA	17.75 ± 2.660bA	30.85 ± 2.920aA	16.42 ± 1.305bA
23	Styrene	87	Sweet smell	[49]	AH	15.76 ± 1.719bB	42.52 ± 7.501abB	66.04 ± 17.135aA	32.90 ± 3.271bA	61.74 ± 5.802aA	35.94 ± 4.774bB
24	3-Octanone *	89	Mushroom-like/buttery	[58]	Ket	n.d.	n.d.	n.d.	192.64 ± 49.231b	400.72 ± 37.208a	181.33 ± 18.574b
25	β-Ocimene	87	Sweet, herb	[54]	Te&Ts	18.66 ± 2.322b	34.83 ± 9.189a	42.49 ± 4.247a	n.d.	n.d.	n.d.
26	o-Cymene	96	Gasoline, citrus	[54,59]	Te&Ts	56.15 ± 11.023bB	153.78 ± 18.436aA	151.50 ± 28.686aA	94.46 ± 15.536bA	172.38 ± 21.329aA	86.03 ± 15.595bB
27	Isoamyl butyrate	90	Green, fruity	[60]	Es	n.d.	n.d.	n.d.	25.73 ± 5.723b	66.30 ± 16.486a	55.30 ± 5.393a
28	Acetoin	96	Sour milk	[51]	Ket	185.42 ± 44.259cB	484.17 ± 63.701aB	331.24 ± 59.406bA	439.72 ± 24.064bA	1026.19 ± 125.392aA	283.79 ± 6.800bA
29	3-Methylacetoin	87	-	-	Ket	6.87 ± 0.932bB	13.14 ± 0.796aA	8.24 ± 1.433bB	18.18 ± 2.239aA	17.12 ± 4.537aA	17.12 ± 4.537aA
30	1-Butoxy-2-propanol	94	-	-	Alc	7.00 ± 1.595bB	33.38 ± 5.554aB	25.65 ± 4.623aA	33.53 ± 4.275bA	58.20 ± 7.734aA	28.39 ± 3.179bA
31	1-Hexanol	96	Sweet, green	[49]	Alc	28.91 ± 5.329aB	62.36 ± 46.499aB	95.27 ± 14.049aB	623.90 ± 309.213aA	552.70 ± 159.944aA	528.37 ± 238.769aA
32	1-Octenyl acetate	95	-	-	Es	n.d.	n.d.	n.d.	426.19 ± 57.704b	775.69 ± 80.136a	402.63 ± 25.727b
33	3-Octanol	84	Mushroom, cheese	[54]	Alc	n.d.	n.d.	n.d.	52.82 ± 5.691b	89.54 ± 9.653a	67.24 ± 10.446b
34	Hexyl butyrate	93	Fruity, green	[61]	Es	n.d.	n.d.	n.d.	17.50 ± 2.985b	34.34 ± 1.539a	19.27 ± 3.282b
35	Acetic acid	95	Vinegar, sour, sharp, peppery, green	[51]	CA	92.92 ± 21.149bB	445.64 ± 79.887aA	605.66 ± 92.910aA	226.10 ± 45.177cA	562.83 ± 68.060aA	363.00 ± 28.421bB
36	trans-Linalool oxide (isomer)	95	-	-	Te&Ts	n.d.	n.d.	n.d.	638.94 ± 108.438b	1247.76 ± 186.259a	633.61 ± 60.692b
37	1-Octen-3-ol	97	Mushroom, metallic	[54]	Alc	5.90 ± 1.212bB	10.13 ± 0.379abB	11.35 ± 2.807aB	84.88 ± 9.979bA	160.27 ± 25.469aA	82.59 ± 2.777bA
38	trans-2-Pinanol	86	-	-	Te&Ts	n.d.	n.d.	n.d.	17.53 ± 1.531b	30.69 ± 3.142a	19.49 ± 3.055b
39	trans-Linalool oxide (isomer)	97	-	-	Te&Ts	n.d.	n.d.	n.d.	327.46 ± 49.616b	558.54 ± 25.266a	305.77 ± 29.301b
40	Linalyl acetate	72	Flower, fruit, lavender	[54]	Te&Ts	n.d.	n.d.	n.d.	6.97 ± 0.964b	10.38 ± 0.517a	6.33 ± 0.437b
41	2-Ethyl-1-hexanol	90	Mild, oily, sweet, slightly floral odor reminiscent of rose	[49]	Alc	n.d.	n.d.	n.d.	11.11 ± 1.098a	11.17 ± 1.211a	10.57 ± 1.624a
42	Camphor	93	Camphor	[54]	Te&Ts	n.d.	n.d.	n.d.	61.08 ± 7.291b	101.92 ± 6.717a	54.25 ± 4.126b
43	Benzaldehyde	97	Almonds, sugar, burnt	[51]	Ald	49.32 ± 11.585bB	116.58 ± 14.396aB	115.88 ± 24.301aB	211.96 ± 12.459aA	271.88 ± 66.353aA	266.70 ± 52.937aA
44	2,3-Butanediol (optical isomer)	95	Fruity, onions	[51]	Alc	28.42 ± 9.483cA	77.80 ± 11.120bB	145.40 ± 24.605aA	39.73 ± 5.638bA	156.05 ± 25.139aA	119.33 ± 23.194aA
45	Linalool	86	Flower, lavender	[54,62]	Te&Ts	9.49 ± 1.481abB	8.77 ± 0.928bB	15.56 ± 3.930aB	2416.24 ± 313.723bA	4130.24 ± 295.527aA	2371.14 ± 188.355bA
46	Isobutyric acid	94	Cheesy, butter, rancid	[51]	CA	12.31 ± 1.076c	81.03 ± 16.303b	142.94 ± 26.383a	n.d.	n.d.	n.d.
47	Linalyl isobutyrate **	87	Cheesy, butter, rancid	[51]	Te&Ts	n.d.	n.d.	n.d.	2143.98 ± 264.564b	3817.29 ± 361.877a	2297.54 ± 183.074b
48	2,3-Butanediol (meso isomer)	97	Fruity, onions	[51]	Alc	81.21 ± 31.384cA	175.49 ± 32.577bB	307.94 ± 34.889aA	98.55 ± 13.951bA	478.83 ± 157.897aA	215.29 ± 86.648bA
49	4-Terpineol ***	86	Green, liquorice, moldy	[48]	Te&Ts	n.d.	n.d.	n.d.	237.05 ± 30.071b	373.97 ± 35.340a	258.37 ± 31.058b
50	Methyl decanoate	89	-	-	Es	13.02 ± 1.438c	30.64 ± 4.524b	40.91 ± 4.701a	n.d.	n.d.	n.d.
51	Lavandulyl acetate	93	Floral odor reminiscent of lavender	[63]	Te&Ts	n.d.	n.d.	n.d.	211.16 ± 29.910b	355.30 ± 35.686a	216.28 ± 19.026b
52	Butyric acid	93	Parmesan cheese, vomit, butanoic acid	[48]	CA	81.43 ± 21.084cB	212.27 ± 56.676bB	389.59 ± 64.874aA	469.11 ± 26.717aA	643.62 ± 144.232aA	506.19 ± 81.424aA
53	Phenylacetaldehyde	94	Floral, rosy, sweet, hyacinth-like	[62]	Ald	n.d.	n.d.	n.d.	20.02 ± 1.922a	23.38 ± 1.934a	12.98 ± 3.641b
54	Isovaleric acid	94	Sweet, rancid, rotten, cheesy, Swiss cheese	[51]	CA	64.68 ± 6.667cB	373.42 ± 17.242bB	537.57 ± 30.138aB	207.08 ± 13.678cA	553.87 ± 37.967bA	702.86 ± 33.921aA
55	α-Terpineol	83	Oil, anise, mint	[54]	Te&Ts	n.d.	n.d.	n.d.	20.99 ± 2.956b	31.51 ± 2.595a	18.49 ± 3.808b
56	Borneol	95	Camphor	[54]	Te&Ts	n.d.	n.d.	n.d.	155.76 ± 21.932b	250.67 ± 27.919a	145.19 ± 32.109b
57	cis-Geranyl acetate	86	Rose, fruity, flower	[54]	Te&Ts	n.d.	n.d.	n.d.	34.31 ± 3.226b	56.58 ± 6.103a	34.09 ± 6.532b
58	Linalool oxide (isomer)	77	Floral, honey-like	[61]	Te&Ts	n.d.	n.d.	n.d.	10.48 ± 2.264b	15.63 ± 1.521a	9.73 ± 2.250b
59	Caproic acid	93	Bad breath, popcorn, goaty	[51]	CA	185.93 ± 46.042bB	403.05 ± 90.032aB	451.28 ± 36.396aB	807.79 ± 45.073bA	1133.32 ± 206.390aA	722.20 ± 16.136bA
60	2,6-dimethyl-3,7-octadien-2,6-diol	83	-	-	Alc	n.d.	n.d.	n.d.	37.95 ± 6.169b	65.88 ± 5.583a	43.95 ± 2.542b
61	Caryophyllene oxide	87	Terpene notes, weak woody–spicy	[64]	Te&Ts	n.d.	n.d.	n.d.	26.76 ± 3.983b	47.81 ± 1.866a	31.78 ± 4.108b
62	Caprylic acid	97	Sweaty, rancid	[51]	CA	76.51 ± 7.885bB	188.50 ± 28.549aB	192.79 ± 32.975aA	193.80 ± 21.998bA	342.19 ± 29.252aA	240.40 ± 41.430bA
					TOTAL, of which:	3337.08	10,392.16	14,743.17	16,366.71	29,619.78	19,695.86
					Alc	775.14	2496.84	3551.32	2533.80	4577.67	2783.98
					Ald	71.77	123.26	115.88	263.50	302.12	299.12
					AH	38.79	94.52	131.71	32.90	130.69	77.05
					CA	513.79	1703.91	2319.84	1903.87	3235.83	2534.65
					CyAlka	275.86	1083.19	1636.99	575.97	1495.49	1022.22
					Es	270.86	540.06	680.26	1278.34	1921.57	1138.26
					HoAlka	1068.81	3527.63	5590.37	2176.24	4329.89	4329.89
					Ket	198.46	510.93	363.26	661.25	1474.94	509.98
					Pyr	12.38	50.35	63.41	21.12	21.45	10.31
					Te&Ts	111.21	261.48	290.13	6919.72	12130.13	6990.40

* 3-octanone was identified along with β-ocimene in LC; ** linalyl isobutyrate was identified along with isobutyric acid in LC; *** 4-terpineol was identified along with methyl decanoate in LC; MSS—mass spectra similarity; T1—10 days of ripening; T2—20 days of ripening; T3—30 days of ripening; CC—chemical class; Es—esters; Alc—alcohols; CyAlka—cyanoalkanes; HoAlka—haloalkanes; AH—aromatic hydrocarbons; Ald—aldehydes; Te&Ts—terpene and terpenoids; Pyr—pyridines; Ket—ketones; CA—carboxylic acids; n.d.—not detected. Data are expressed as mean ± standard deviation values of all measurements. Different lowercase letters in the same row indicate significant differences between ripening times (p < 0.05, Tukey’s test), and different uppercase letters show significant differences between cheeses (p < 0.05).

Table 4. Volatile compound concentrations in control and lavender Gouda-type cheese at different ripening times (T1, T2, and T3).

Crt.No.	Volatile Compound	MSS (%)	Odor Descriptor	Reference	CC	Control Cheese			Lavender Cheese
						µg/kg Cheese
						T1	T2	T3	T1	T2	T3
1	Methyl acetate	96	Fruity, solvent, blackcurrant-like	[48]	Es	38.56 ± 4.199bB	67.26 ± 2.948bB	111.20 ± 26.935aA	53.50 ± 1.607bA	115.42 ± 25.312aA	61.89 ± 5.974bB
2	Isopropanol	97	Sharp musty	[49]	Alc	221.75 ± 46.558cB	722.34 ± 89.846bB	1155.17 ± 222.182aA	599.38 ± 75.037bA	1047.99 ± 120.237aA	590.10 ± 7.424bB
3	Methyl butyrate	96	Fruity, apple-like	[50]	Es	54.21 ± 11.983bB	114.20 ± 17.312aB	153.96 ± 31.418aA	180.06 ± 25.014aA	222.23 ± 34.620aA	170.39 ± 1.721aA
4	Acetonitrile	98	-	-	CyAlka	275.86 ± 51.660cB	1083.19 ± 169.607bA	1636.99 ± 279.534aA	575.97 ± 89.883cA	1495.49 ± 197.115aA	1022.22 ± 52.569bB
5	Chloroform	77	Ether-like	[49]	HoAlka	1068.81 ± 206.553cB	3527.63 ± 402.152bA	5590.37 ± 1139.680aA	2176.24 ± 339.353bA	4329.89 ± 565.593aA	4329.89 ± 565.593aA
6	Toluene	94	Nutty, bitter, almonds, paint; fruity	[51,52]	AH	23.03 ± 3.945b	51.99 ± 9.667abA	65.66 ± 18.515aA	n.d.	68.95 ± 22.883aA	41.11 ± 5.903aA
7	Ethyl butyrate (isomer)	95	Fruity, pineapple, acetone, caramel	[48]	Es	n.d.	n.d.	n.d.	39.08 ± 2.587a	50.16 ± 15.106a	28.71 ± 12.886a
8	Butyl acetate	94	Fruity	[49]	Es	15.34 ± 3.106aB	25.07 ± 3.967aA	23.29 ± 5.877aA	27.71 ± 2.459aA	22.75 ± 2.323bA	13.80 ± 0.133cB
9	Hexanal	95	Cut grass	[53]	Ald	16.51 ± 5.051aA	6.68 ± 2.494bA	n.d.	31.52 ± 20.601aA	6.86 ± 2.523aA	19.44 ± 0.720a
10	Isobutanol	91	Choking alcohol	[49]	Alc	6.31 ± 1.424bB	24.40 ± 3.487aB	28.14 ± 8.926aA	12.67 ± 3.009cA	34.31 ± 1.756aA	20.10 ± 3.050bA
11	Isoamyl acetate	97	Banana, chewing gum	[48]	Es	n.d.	n.d.	n.d.	n.d.	62.98 ± 10.744a	52.95 ± 4.624a
12	1-Butanol	97	Medicinal, fruity	[51]	Alc	201.21 ± 41.648cB	640.06 ± 83.138bA	950.89 ± 166.505aA	505.86 ± 71.458aA	638.14 ± 80.605aA	319.35 ± 28.604bB
13	β-Myrcene	93	Balsamic, spice	[54]	Te&Ts	n.d.	n.d.	n.d.	29.92 ± 9.055b	62.30 ± 6.066a	38.28 ± 2.828b
14	Pyridine	92	-	-	Pyr	12.38 ± 3.015bA	50.35 ± 9.850aA	63.41 ± 11.766aA	21.12 ± 6.264aA	21.45 ± 2.673aB	10.31 ± 1.399bB
15	2-Heptanone	88	Fruity	[52]	Ket	6.17 ± 1.257cA	13.62 ± 2.483bB	23.78 ± 1.680aA	10.71 ± 2.732bA	30.92 ± 3.245aA	27.73 ± 2.546aA
16	Heptanal	80	Sour milk/dairy	[52]	Ald	5.94 ± 1.317	n.d.	n.d.	n.d.	n.d.	n.d.
17	Methyl hexanoate	96	Fruity, ester-like	[50]	Es	141.11 ± 25.302bB	288.30 ± 40.965aB	321.42 ± 53.508aA	428.97 ± 58.989aA	496.81 ± 69.633aA	279.30 ± 29.445bA
18	1,8-Cineole	97	Floral, minty, fruity	[54]	Te&Ts	n.d.	n.d.	n.d.	370.96 ± 56.128b	678.05 ± 61.261a	356.96 ± 17.757b
19	Isoamyl alcohol	97	Banana	[55]	Alc	194.44 ± 43.626bB	750.88 ± 94.873aB	831.51 ± 172.253aA	433.41 ± 95.289cA	1284.59 ± 151.738aA	758.69 ± 54.400bA
20	Ethyl butyrate (isomer)	96	Pineapple-like	[49]	Es	8.62 ± 2.144bB	14.59 ± 2.407bB	29.48 ± 7.633aA	79.59 ± 8.303aA	74.89 ± 2.553aA	54.02 ± 9.024bB
21	trans-β-Ocimene	82	Mushroom-like	[56]	Te&Ts	21.33 ± 4.752cA	50.26 ± 4.803bB	66.13 ± 7.807aB	97.95 ± 13.079bB	158.27 ± 8.496aA	90.65 ± 9.332bA
22	ɣ-Terpinene	83	Unpleasant	[57]	Te&Ts	5.57 ± 0.261bB	13.84 ± 1.000aB	14.45 ± 1.618aA	17.75 ± 2.660bA	30.85 ± 2.920aA	16.42 ± 1.305bA
23	Styrene	87	Sweet smell	[49]	AH	15.76 ± 1.719bB	42.52 ± 7.501abB	66.04 ± 17.135aA	32.90 ± 3.271bA	61.74 ± 5.802aA	35.94 ± 4.774bB
24	3-Octanone *	89	Mushroom-like/buttery	[58]	Ket	n.d.	n.d.	n.d.	192.64 ± 49.231b	400.72 ± 37.208a	181.33 ± 18.574b
25	β-Ocimene	87	Sweet, herb	[54]	Te&Ts	18.66 ± 2.322b	34.83 ± 9.189a	42.49 ± 4.247a	n.d.	n.d.	n.d.
26	o-Cymene	96	Gasoline, citrus	[54,59]	Te&Ts	56.15 ± 11.023bB	153.78 ± 18.436aA	151.50 ± 28.686aA	94.46 ± 15.536bA	172.38 ± 21.329aA	86.03 ± 15.595bB
27	Isoamyl butyrate	90	Green, fruity	[60]	Es	n.d.	n.d.	n.d.	25.73 ± 5.723b	66.30 ± 16.486a	55.30 ± 5.393a
28	Acetoin	96	Sour milk	[51]	Ket	185.42 ± 44.259cB	484.17 ± 63.701aB	331.24 ± 59.406bA	439.72 ± 24.064bA	1026.19 ± 125.392aA	283.79 ± 6.800bA
29	3-Methylacetoin	87	-	-	Ket	6.87 ± 0.932bB	13.14 ± 0.796aA	8.24 ± 1.433bB	18.18 ± 2.239aA	17.12 ± 4.537aA	17.12 ± 4.537aA
30	1-Butoxy-2-propanol	94	-	-	Alc	7.00 ± 1.595bB	33.38 ± 5.554aB	25.65 ± 4.623aA	33.53 ± 4.275bA	58.20 ± 7.734aA	28.39 ± 3.179bA
31	1-Hexanol	96	Sweet, green	[49]	Alc	28.91 ± 5.329aB	62.36 ± 46.499aB	95.27 ± 14.049aB	623.90 ± 309.213aA	552.70 ± 159.944aA	528.37 ± 238.769aA
32	1-Octenyl acetate	95	-	-	Es	n.d.	n.d.	n.d.	426.19 ± 57.704b	775.69 ± 80.136a	402.63 ± 25.727b
33	3-Octanol	84	Mushroom, cheese	[54]	Alc	n.d.	n.d.	n.d.	52.82 ± 5.691b	89.54 ± 9.653a	67.24 ± 10.446b
34	Hexyl butyrate	93	Fruity, green	[61]	Es	n.d.	n.d.	n.d.	17.50 ± 2.985b	34.34 ± 1.539a	19.27 ± 3.282b
35	Acetic acid	95	Vinegar, sour, sharp, peppery, green	[51]	CA	92.92 ± 21.149bB	445.64 ± 79.887aA	605.66 ± 92.910aA	226.10 ± 45.177cA	562.83 ± 68.060aA	363.00 ± 28.421bB
36	trans-Linalool oxide (isomer)	95	-	-	Te&Ts	n.d.	n.d.	n.d.	638.94 ± 108.438b	1247.76 ± 186.259a	633.61 ± 60.692b
37	1-Octen-3-ol	97	Mushroom, metallic	[54]	Alc	5.90 ± 1.212bB	10.13 ± 0.379abB	11.35 ± 2.807aB	84.88 ± 9.979bA	160.27 ± 25.469aA	82.59 ± 2.777bA
38	trans-2-Pinanol	86	-	-	Te&Ts	n.d.	n.d.	n.d.	17.53 ± 1.531b	30.69 ± 3.142a	19.49 ± 3.055b
39	trans-Linalool oxide (isomer)	97	-	-	Te&Ts	n.d.	n.d.	n.d.	327.46 ± 49.616b	558.54 ± 25.266a	305.77 ± 29.301b
40	Linalyl acetate	72	Flower, fruit, lavender	[54]	Te&Ts	n.d.	n.d.	n.d.	6.97 ± 0.964b	10.38 ± 0.517a	6.33 ± 0.437b
41	2-Ethyl-1-hexanol	90	Mild, oily, sweet, slightly floral odor reminiscent of rose	[49]	Alc	n.d.	n.d.	n.d.	11.11 ± 1.098a	11.17 ± 1.211a	10.57 ± 1.624a
42	Camphor	93	Camphor	[54]	Te&Ts	n.d.	n.d.	n.d.	61.08 ± 7.291b	101.92 ± 6.717a	54.25 ± 4.126b
43	Benzaldehyde	97	Almonds, sugar, burnt	[51]	Ald	49.32 ± 11.585bB	116.58 ± 14.396aB	115.88 ± 24.301aB	211.96 ± 12.459aA	271.88 ± 66.353aA	266.70 ± 52.937aA
44	2,3-Butanediol (optical isomer)	95	Fruity, onions	[51]	Alc	28.42 ± 9.483cA	77.80 ± 11.120bB	145.40 ± 24.605aA	39.73 ± 5.638bA	156.05 ± 25.139aA	119.33 ± 23.194aA
45	Linalool	86	Flower, lavender	[54,62]	Te&Ts	9.49 ± 1.481abB	8.77 ± 0.928bB	15.56 ± 3.930aB	2416.24 ± 313.723bA	4130.24 ± 295.527aA	2371.14 ± 188.355bA
46	Isobutyric acid	94	Cheesy, butter, rancid	[51]	CA	12.31 ± 1.076c	81.03 ± 16.303b	142.94 ± 26.383a	n.d.	n.d.	n.d.
47	Linalyl isobutyrate **	87	Cheesy, butter, rancid	[51]	Te&Ts	n.d.	n.d.	n.d.	2143.98 ± 264.564b	3817.29 ± 361.877a	2297.54 ± 183.074b
48	2,3-Butanediol (meso isomer)	97	Fruity, onions	[51]	Alc	81.21 ± 31.384cA	175.49 ± 32.577bB	307.94 ± 34.889aA	98.55 ± 13.951bA	478.83 ± 157.897aA	215.29 ± 86.648bA
49	4-Terpineol ***	86	Green, liquorice, moldy	[48]	Te&Ts	n.d.	n.d.	n.d.	237.05 ± 30.071b	373.97 ± 35.340a	258.37 ± 31.058b
50	Methyl decanoate	89	-	-	Es	13.02 ± 1.438c	30.64 ± 4.524b	40.91 ± 4.701a	n.d.	n.d.	n.d.
51	Lavandulyl acetate	93	Floral odor reminiscent of lavender	[63]	Te&Ts	n.d.	n.d.	n.d.	211.16 ± 29.910b	355.30 ± 35.686a	216.28 ± 19.026b
52	Butyric acid	93	Parmesan cheese, vomit, butanoic acid	[48]	CA	81.43 ± 21.084cB	212.27 ± 56.676bB	389.59 ± 64.874aA	469.11 ± 26.717aA	643.62 ± 144.232aA	506.19 ± 81.424aA
53	Phenylacetaldehyde	94	Floral, rosy, sweet, hyacinth-like	[62]	Ald	n.d.	n.d.	n.d.	20.02 ± 1.922a	23.38 ± 1.934a	12.98 ± 3.641b
54	Isovaleric acid	94	Sweet, rancid, rotten, cheesy, Swiss cheese	[51]	CA	64.68 ± 6.667cB	373.42 ± 17.242bB	537.57 ± 30.138aB	207.08 ± 13.678cA	553.87 ± 37.967bA	702.86 ± 33.921aA
55	α-Terpineol	83	Oil, anise, mint	[54]	Te&Ts	n.d.	n.d.	n.d.	20.99 ± 2.956b	31.51 ± 2.595a	18.49 ± 3.808b
56	Borneol	95	Camphor	[54]	Te&Ts	n.d.	n.d.	n.d.	155.76 ± 21.932b	250.67 ± 27.919a	145.19 ± 32.109b
57	cis-Geranyl acetate	86	Rose, fruity, flower	[54]	Te&Ts	n.d.	n.d.	n.d.	34.31 ± 3.226b	56.58 ± 6.103a	34.09 ± 6.532b
58	Linalool oxide (isomer)	77	Floral, honey-like	[61]	Te&Ts	n.d.	n.d.	n.d.	10.48 ± 2.264b	15.63 ± 1.521a	9.73 ± 2.250b
59	Caproic acid	93	Bad breath, popcorn, goaty	[51]	CA	185.93 ± 46.042bB	403.05 ± 90.032aB	451.28 ± 36.396aB	807.79 ± 45.073bA	1133.32 ± 206.390aA	722.20 ± 16.136bA
60	2,6-dimethyl-3,7-octadien-2,6-diol	83	-	-	Alc	n.d.	n.d.	n.d.	37.95 ± 6.169b	65.88 ± 5.583a	43.95 ± 2.542b
61	Caryophyllene oxide	87	Terpene notes, weak woody–spicy	[64]	Te&Ts	n.d.	n.d.	n.d.	26.76 ± 3.983b	47.81 ± 1.866a	31.78 ± 4.108b
62	Caprylic acid	97	Sweaty, rancid	[51]	CA	76.51 ± 7.885bB	188.50 ± 28.549aB	192.79 ± 32.975aA	193.80 ± 21.998bA	342.19 ± 29.252aA	240.40 ± 41.430bA
					TOTAL, of which:	3337.08	10,392.16	14,743.17	16,366.71	29,619.78	19,695.86
					Alc	775.14	2496.84	3551.32	2533.80	4577.67	2783.98
					Ald	71.77	123.26	115.88	263.50	302.12	299.12
					AH	38.79	94.52	131.71	32.90	130.69	77.05
					CA	513.79	1703.91	2319.84	1903.87	3235.83	2534.65
					CyAlka	275.86	1083.19	1636.99	575.97	1495.49	1022.22
					Es	270.86	540.06	680.26	1278.34	1921.57	1138.26
					HoAlka	1068.81	3527.63	5590.37	2176.24	4329.89	4329.89
					Ket	198.46	510.93	363.26	661.25	1474.94	509.98
					Pyr	12.38	50.35	63.41	21.12	21.45	10.31
					Te&Ts	111.21	261.48	290.13	6919.72	12130.13	6990.40

* 3-octanone was identified along with β-ocimene in LC; ** linalyl isobutyrate was identified along with isobutyric acid in LC; *** 4-terpineol was identified along with methyl decanoate in LC; MSS—mass spectra similarity; T1—10 days of ripening; T2—20 days of ripening; T3—30 days of ripening; CC—chemical class; Es—esters; Alc—alcohols; CyAlka—cyanoalkanes; HoAlka—haloalkanes; AH—aromatic hydrocarbons; Ald—aldehydes; Te&Ts—terpene and terpenoids; Pyr—pyridines; Ket—ketones; CA—carboxylic acids; n.d.—not detected. Data are expressed as mean ± standard deviation values of all measurements. Different lowercase letters in the same row indicate significant differences between ripening times (p < 0.05, Tukey’s test), and different uppercase letters show significant differences between cheeses (p < 0.05).

3.5. Sensory Properties of Gouda-Type Cheese and Consumers’ Acceptance and Purchase Intention

Consumers’ perception of LC compared to CC was evaluated based on hedonic scores of their sensory attributes (Figure 4). The use of lavender flower powder as a flavoring ingredient in Gouda-type cheese-making has significantly affected its sensory properties by reducing its rating for appearance and color (0.6 points), consistency and texture (0.7 points), odor and taste (1.2 points), aftertaste (1.1 points), and overall liking (0.7 points). The overall score for LC was 7.2, and that for CC was 8.1. However, the calculation resulted in an acceptance rate of 80.2% for LC and 89.5% for CC. Furthermore, when asked about their willingness to buy the Gouda-type cheese, 34% of respondents answered that they “definitely will buy” LC, and 42% responded in this way for CC (see Figure 5). As regards the undecided subjects, 24% answered “might or might not buy” and 8% “probably will buy” the LC, which shows greater indecision about the flavored cheese. This outcome highlights the lack of familiarity but a curiosity towards this new product. For LC, 8% of survey participants responded with “definitely will not buy”. Overall, these results show that there would be customers for LC if this were available on the market.

4. Conclusions

The manufacturing process proposed in this study resulted in a Gouda-type cheese formulation with a lavender aroma. Using lavender flower powder as a flavoring ingredient at a concentration of 0.5 g/L matured milk in Gouda-type cheese manufacturing conferred upon the cheese a terpenic volatile profile and stimulated the growth of lactic acid bacteria from the starter culture. During ripening, a concentration of volatile compounds and lactic acid bacteria, both in the control and lavender cheese, and an improvement in their nutritional and textural properties was noticed. However, it should be underlined that the flavoring ingredient did not significantly impact the Gouda-type cheese’s gross composition and textural properties. Regarding the sensory perception of the lavender cheese, it should be noted that its overall score was slightly lower but very close to that received by the unflavored cheese, definitively more familiar. Although the acceptance rate of the lavender-flavored cheese was high, consumers were less willing to buy it, being a gourmet product. However, with effective communication of this new product, perhaps accompanied by a food pairing study, the lavender-flavored Gouda-type cheese could be a successful novelty in the worldwide dairy market.