Physicochemical, Sensory Properties and Lipid Oxidation of Chicken Sausages Supplemented with Three Types of Seaweed

Abstract

The effect of the addition of three types of tropical edible seaweeds, Kappaphycus alvarezii (KA), Sargassum polycystum (SP), and Caulerpa lentilifira (CL), on sausages were studied. Nine sausage formulations with three levels of inclusion (2%, 4%, and 6%) of each seaweed were prepared, analysed, and compared with the control sample (without seaweed) in terms of their physicochemical properties, total phenolic content, and lipid oxidation. The modified sausages had low moisture and fat content (p < 0.05) but high ash and dietary fiber content (p < 0.05) compared to the control sausage. The addition of seaweed powder changed the texture of the sausages, mainly its hardness and chewiness (p < 0.05), but no significant difference in cohesiveness and springiness was found (p < 0.05). The modified sausages were shown to have high water holding capacities and cooking yields. The different types of seaweed modified the colour of the chicken sausages differently. In general, the L* (brightness) and b* (yellowness) values was low for all sausage samples containing seaweed powder (p < 0.05), while the a* (redness) value increased with the addition of the KA and SP seaweed powder but decreased for the sausage sample with added CL seaweed powder (p < 0.05). Moreover, the modified sausages have higher total phenolic contents and high antioxidant capacities, which contributed to slowing the oxidation of lipid in sausages during storage (p < 0.05). Sensory evaluation showed that the panellists found up to 4% of KA and 2% of SP to be acceptable. Overall, the seaweeds, especially KA and SP, could potentially be developed as excellent additives for the manufacture of highly technological high-quality meat products.

1. Introduction

Meat and meat products offer numerous nutritional values, providing a good source of high-quality protein, fat-soluble vitamins, minerals, and essential fatty acids. It is a core part of the human diet; thus, good-quality meat products are crucial for a healthy, balanced diet [1]. However, they also contain components that may enhance the risk of major degenerative and chronic diseases such as heart disease and cancer when consumed in inappropriate quantities [2]. The growing interest in the relationship between diet and health, combined with consumer demand for healthy, nutritious foods with other health promoting functions, led to the development of functional foods, which presents a challenge for the meat industry’s future.

Generally, reformulation has been widely used to remove, reduce, increase, add, and replace different bioactive components and obtain specific meat-based formulations with particular attributes that fulfill the health-promoting properties [3]. Healthier meat products have been prepared using a variety of ingredients, primarily of plant origins, such as soy, walnut, oils, rice, wheat, and carrot, to improve fat content, incorporate antioxidants, prebiotics, and dietary fiber [4]. In this sense, marine plants such as seaweeds offer interesting new avenues for exploration.

Seaweeds have been incorporated in the diets of coastal cultures for centuries; however, the limited acceptance of seaweed-dominant foods in Western diets may be attributed to expectations of undesirable sensory characteristics, compounded by the lack of familiarity [5]. Despite the current consumption and accessibility to seaweed, the unfamiliar novel food can benefit from rising consumer trends such as flexitarian diets. Seaweeds have been very attractive to consumers as they provide low-calorie content with a high level of significant nutrients. Seaweeds by dry weight are an abundant source of protein, ranging from 6.5–24.4% and low percentages of lipids (about 1%) [6]. Interestingly, these algae possessed high polyunsaturated fatty acids (PUFAs), although they contained low lipid levels. Additionally, seaweeds are roughly 50% carbohydrates by dry weight [7], a rich source of fiber [8], and a significant amount of vitamins A, C, and E [9]. The most prominent macrominerals in seaweeds include sodium, calcium, and potassium, while the microminerals include iron, nickel, cobalt, copper, and manganese [10].

In food manufacturing, seaweed is often incorporated into processed food products, where it serves as a texturing agent and stabilizer [11]. In a previous study, adding Ascophyllum nodosum and Chondrus crispus to whole-wheat bread at 4% and 2% levels, respectively, resulted in the highest ash and total dietary fiber with no aftertaste, soft and chewy texture [12]. Seaweed powder (Kappaphycus alvarezii) was incorporated with wheat flour to produce muffins. The authors found that an increase in the seaweed component reduced the muffin height, volume, and specific volume [13]. When the liquid extract and puree-like mixture of Laminaria ochroleuca were added in gluten-free pasta, it was found that the formulated pasta had similar mechanical and texture characteristics to the control [14]. Furthermore, Sargassum polycystum ethanol extract acts as an antibacterial compound similar to chlorine water in the Tilapia fillet [15]. Despite nutritional, physicochemical, and textural advantages that present edible seaweeds, so far, their applications in the meat sector to design functional meat products with promising health benefits has been little explored. Furthermore, the presence of heavy metals such as mercury at high concentrations in seaweed could limit its use.

Hence, this study aimed to evaluate the effects of three types of seaweed, namely, K. alvarezii (KA), S. polycystum (SP), and C. lentilifira (CL), at different inclusion levels, on the physicochemical properties and lipid oxidation of chicken sausages. These seaweeds are widely consumed in Asian countries, and they are safe for consumption as heavy metals were not detected in these seaweeds [16]. Although these seaweeds have the potential for bioaccumulation, but not permanent accumulation as heavy metals can be released during postharvest processing [17].

2. Materials and Methods

2.1. Preparation and Processing of Seaweed

Fresh Kappaphycus alvarezii (KA), Sargassum polycystum (SP), and Caulerpa lentilifira (CL) seaweeds were supplied by the Seaweed Research Unit, Universiti Malaysia Sabah. All seaweeds were washed with tap water to remove dirt and epiphytes. They were cut to short segments 3–4 cm in length before being dried in a drying cabinet (Thermoline, NSW, Australia) at 45 °C until a constant weight was achieved. The pieces of seaweed were ground using a spice grinder and passed through a 250 µm mesh sieve. Powders of KA, SP, and CL were then placed in individual airtight containers and stored at room temperature until their use for product preparation. The chemical composition and the phenolic content of the seaweeds are given in

Table 1. Chemical composition and phenolic content of Kappaphycus alvarezii (KA), Sargassum polycystum (SP), and Caulerpa lentilifira (CL) seaweed.

Characteristics	Kappaphycus alvarezii (KA)	Sargassum polycystum (SP)	Caulerpa lentilifira (CL)
Moisture content, %	16.67 ± 0.20 A	15.28 ± 0.01 B	11.91 ± 0.01 C
Ash content, %	33.99 ± 0.39 A	34.12 ± 0.21 A	32.70 ± 1.65 A
Protein content, %	5.08 ± 0.02 B	5.20 ± 0.02 B	11.68 ± 0.15 A
Fat content, %	1.26 ± 0.04 B	0.24 ± 0.10 B	2.88 ± 0.05 A
Total dietaryfiber, %	24.79 ± 0.58 B	38.05 ± 0.21 A	34.42 ± 0.41 B
Total phenolic content (mg GAE/g)	1.65 ± 0.06 B	2.25 ± 0.06 B	7.18 ± 0.66 A
DPPH (SA%)	52.40 ± 0.30 C	54.29 ± 0.06 B	57.22 ± 0.91 A

Mean ± standard deviation in the same row with different superscript alphabets (^A–C) indicates there are significant differences (p < 0.05).

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2.2. Chicken Sausage Preparation and Processing

Boneless chicken breasts were purchased from Desa Hatchery Sdn. Bhd. and ground with a meat mincer pass through a grinder with 0.5 mm (Hanchen, Guangzhou, China) before being stored in a refrigerator (REVCO, California, USA) at 0 °C. Three different sausage formulations were prepared with varying levels of seaweed included (2%, 4%, and 6%) for each. One batch of sausages was prepared without any seaweed (0% seaweed) as a control. In total, there are nine treatments and one control. The sausage preparation followed the formulations described by [18], and the experimental design and compositions are given in

Table 2. Chicken sausage formulations.

Ingredients	Treatments (g/100 g)
	Control	F2	F4	F6
Chicken meat	65	65	65	65
Fat	10	10	10	10
Ice water	14.9	14.9	14.9	14.9
Isolate soy protein	5	5	5	5
Potato starch	3	3	3	3
Salt	1.5	1.5	1.5	1.5
Other seasoning	0.6	06	0.6	0.6
Total	100	100	100	100
KA	0	2	4	6
SP	0	2	4	6
CL	0	2	4	6

Control (without seaweed); F2 (added 2% seaweed); F4 (added 4% seaweed); F6 (added 6% seaweed).

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The chicken meat was comminuted in a chilled cutter for 1 min. Salt was dissolved in ice water, and the seaweed powder was dispersed, and the mixture was added to the ground meat and mixed again for another 1 min. Other ingredients, such as chicken fat, soy protein isolate, potato starch, and spices, were added simultaneously and mixed for 1 min. After that, the meat batter was homogenised under vacuum for 3 min. A temperature probe was used to monitor the batter temperature, which was maintained below 15 °C throughout batter preparation. The meat batter was then stuffed into a cellulose casing (2.5 cm diameter). Finally, the chicken sausage was cooked in a water bath (80 °C) for 30 min. The cooked sausage was cooled in cool water (<8 °C) for 30 min. The cooked sausage sample was stored at 4 ± 1.00 °C overnight before further analysis [19].

2.3. Proximate Composition and Total Dietary Fiber (TDF)

The composition of the chicken sausages were analyzed according to the standard [20]. Moisture content was determined by weight loss after an overnight of drying at 105 °C in a drying oven (Thermoline, Sydney Australia). Fat content was determined by the Soxhlet method with a solvent extraction system (FOSS Tecator the Soxtec™ 2043, Foss Hoganas, Denmark), and protein content was determined by the Kjeldahl method with an automatic Kjeldahl nitrogen analyser (Kjeltec^® 2300 Analyzer Unit, Foss Hoganas, Sweden). Ash was determined according to the AOAC method 920.153 (muffle furnace). Meanwhile, total dietary fiber was determined by the Megazyme analysis kit (Sigma-Aldrich Inc., Missouri, USA) based on the AOAC method of 991.43.

2.4. Water Holding Capacity

Water holding capacity was determined by using the centrifugation method, which has been modified according to [21]. Sausage samples weighing 5 g were loaded into a centrifugation tube and were centrifuged at 4 °C and 15,000× g for 15 min. The water holding capacity was determined as the liquid loss and expressed as a percentage of the weight of liquid loss:

$$\mathrm{Water}\mathrm{holding}\mathrm{capacity}(\%)=\left(\frac{a-b}{b}\right)\times 100\%$$

(1)

where a is weight before the centrifuge (g) and b is the weight after the centrifuge (g).

2.5. Cooking Loss

Sausage samples were cooked in a steamer for 30 min at 80 °C and then cooled for 30 min. The sausage samples were weighed before and after cooking. Cooking loss was calculated from the differences in the weight of uncooked and cooked samples, expressed as the percentage of initial weight,

$$\mathrm{Cooking}\mathrm{loss}(\%)=\left(\frac{a-b}{b}\right)\times 100\%$$

(2)

where a initial weight before cooked (g) and b is the sausage sample after cooked (g).

2.6. Colour

Ten samples from each formulation were evaluated for colour analysis using a HunterLab Colorimeter (HunterLab, Virginia, USA). CIE L*—(lightness), a*—(redness) and b*—(yellowness) values were measured to evaluate the colouring effects of the three types of seaweeds added. The colorimeter was calibrated against a standard white reference tile (L* = 93.97; a* = −0.08, and b* = 1.21).

2.7. Texture Profile Analysis (TPA)

Hardness (N), cohesiveness, springiness (mm), and chewiness (N.mm) were measure using a TA.XT Plus texture analyser (Stable Micro System, Surrey, UK) performed at room temperature [22]. Measurements were made on 2.0 cm height and 2.0 cm diameter, 3.5 cm diameter probe rod, and 40% compression from initial height, and 5 kg force applied at a constant crosshead speed of 1.5 mm/s. Ten replications of each sample were carried out.

2.8. Sensory Evaluation

The chicken sausages were evaluated for appearance, colour, aroma, taste, hardness, juiciness, and overall acceptance. This evaluation used a seven-point hedonic scale (1 = extremely dislike, 7 = extremely like). The sausage was cut uniformly and offered in random order. The samples were serves at the same time on plate with random three-digit numbers, and water at room temperature was provided for mouth rinsing between samples. Forty untrained students of the Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, were chosen to form the sensory panelist set.

2.9. Sample Extraction

Sausage samples were extracted using a method described by [23] with slight modification. The sausage samples were extracted in 20 mL methanol and homogenised in a dark room for 30 min. The sample extract was filtered and centrifuged (KUBOTA 2100, Tokyo, Japan) at a speed of 10,000 rpm.

2.10. Measurement of Total Phenolic Content (TPC)

The total phenolic content of the sausages was determined spectrophotometrically through the method described by [21]. The extract solutions (0.1 mL) were mixed with 1.0 mL of Folin–Ciocalteu reagent. After 5 min of reaction, 1.0 mL of Na2CO3 (7.5%) was added to distilled water until it reached 10 mL solution. The solution’s absorbance was measured in a spectrophotometer at 750 nm after 30 min of incubation in the darkroom. TPC was expressed in gallic acid equivalents (GAE) per 100 g (dry weight) of extract (mg GAE g-1).

2.11. Antioxidant Capacity

The antioxidant capacity of the sausage samples was determined using the diphenyl-hydrazyl (DPPH) assay as described by [24] with slight modification. The DPPH assay was carried out by mixing 0.3 mL of the sample extract with 0.06 mM methanolic DPPH solution. The absorbance of the mixture was measured at 517 nm after 30 min incubation in the darkroom. Pure methanol was used as a control in this analysis. The percentage of DPPH scavenging activity (%SA) was evaluated as follows:

$$\mathrm{DPPH}\mathrm{Scavenging}\mathrm{activity}\left(\%\mathrm{SA}\right)=1-\left(\frac{\mathrm{DPPH}\mathrm{without}\mathrm{sample}-\mathrm{DPPH}\mathrm{with}\mathrm{sample}}{\mathrm{Sample}\mathrm{without}\mathrm{DPPH}}\right)$$

(3)

2.12. Thiobarbituric Acid Reactive Substance (TBARS)

The TBARS values were determined using an extraction method [25]. For extraction, 5 g of sausage sample was homogenised in a bag mixer for 2 min with 7.5% TCA. After filtration with a qualitative filter paper, 2 mL of filtrate was mixed with 2 mL of an aqueous solution (0.02 M TBA). Samples were incubated in a water bath at 95 °C for 35 min and then cooled. The absorbance was measured at 531 nm in a spectrophotometer. The value was calculated from the TEP standard curve and expressed as mg of malonaldehyde (MDA)/kg of a sample. The analysis was performed on days 0, 7, 14, 21, and 28 of storage at 4 °C.

2.13. Statistical Analysis

One-way ANOVA was used to evaluate the effects of different types of seaweed on chicken sausage’s physicochemical and sensory properties. The trial was replicated triplicate (three independent batches), each replication corresponding to a different production day. Data were analysed using SPSS version 24.0 statistical processor software (IBM corp., Armonk, NY, USA). The Tukey test was used to evaluate the significant difference between the means for the various attributes (p < 0.05).

3. Results and Discussion

3.1. Proximate Composition and Total Dietary Fiber

Table 3. Proximate composition and total dietary fiber for chicken sausage incorporate with seaweed.

Parameter	Seaweed Powder Percentage	KA	SP	CL
Moisture	0%	68.87 ± 0.09 a	68.87 ± 0.09 a	68.87 ± 0.09 a
	2%	67.94 ± 0.58 bB	68.75 ± 0.03 aA	68.88 ± 0.28 aA
	4%	67.29 ± 0.22 bA	66.65 ± 0.53 bB	68.30 ± 0.26 aA
	6%	65.43 ± 0.85 cB	66.56 ± 0.44 bA	67.73 ± 0.05 bA
Ash	0%	0.64 ± 0.68 b	0.64 ± 0.68 b	0.64 ± 0.69 a
	2%	0.91 ± 0.09 bA	1.60 ± 0.49 bA	1.15 ± 0.05 aA
	4%	1.33 ± 0.02 abB	3.57 ± 0.54 aA	1.14 ± 0.02 aB
	6%	2.17 ± 0.08 aB	3.93 ± 0.20 aA	1.28 ± 0.10 aC
Protein	0%	19.23 ± 0.66 a	19.23 ± 0.66 a	19.23 ± 0.66 a
	2%	19.49 ± 0.38 aA	19.88 ± 0.01 aA	19.71 ± 0.19 aA
	4%	19.18 ± 0.17 aA	19.84 ± 0.02 aA	19.64 ± 0.03 aA
	6%	19.03 ± 0.02 aA	19.29 ± 0.42 aA	19.56 ± 0.03 aA
Fat	0%	10.11 ± 0.37 a	10.11 ± 0.37 a	10.11 ± 0.37 a
	2%	9.58 ± 0.11 bA	9.76 ± 0.93 bA	9.37 ± 0.46 bA
	4%	8.25 ± 0.74 cB	9.46 ± 0.33 bA	8.97 ± 0.11 cAB
	6%	7.29 ± 0.42 cB	8.50 ± 0.13 bA	8.85 ± 0.39 cA
Dietary fiber	0%	0.07 ± 0.05 c	0.07 ± 0.05 c	0.07 ± 0.05 c
	2%	0.93 ± 0.05 bC	1.22 ± 0.01 bA	1.02 ± 0.01 cB
	4%	1.02 ± 0.03 bC	1.29 ± 0.01 bB	1.47 ± 0.03 bA
	6%	1.38 ± 0.20 aB	2.67 ± 0.11 aA	1.63 ± 0.06 aB

Mean ± standard deviation in the same column with different superscript alphabets (^a–c) indicates there is a significant difference (p < 0.05) with the same type of treatment. Mean ± standard deviation in the same row with different superscript alphabets (^A–C) indicates there are significant difference (p < 0.05). KA: Sausage with added Kappaphycus alvarezii, SP: sausage with added Sargassum polycystum, CL; sausage with added Caulerpa lentilifa.

shows the results for the proximate composition and dietary fiber of the sausage. Regarding the proximate composition, moisture, ash, fat, and total dietary fiber contents showed significant differences (p < 0.05) between the different levels of seaweed added in the sausages. The addition of seaweed (KA, SP, and CL) reduced moisture and fat content (p < 0.05) and raised the dietary fiber content and ash content (p < 0.05) in sausages. However, despite the inclusion of various levels of seaweed to the formulation, no significant difference in protein content was identified.

The chicken sausages with seaweed, regardless of seaweed variety and inclusion level, had a lower moisture content compared to control. This was most likely because the seaweeds had a lower moisture content than chicken meat. Furthermore, the addition of dietary fiber, also in its dry form, reduced the moisture content of the tested samples [26]. Since seaweed contains less fat, as shown in Table 1, the amount of fat in the treated samples decreased significantly (p < 0.05).

Meat does not contain dietary fiber, but a small amount of dietary fiber was detected in the control sausage, which may have been contributed by the condiments and spices. As expected, the TDF of sausages increased significantly (p < 0.05) after the incorporation of seaweed and was more pronounced in the sausages with added S. polycystum (SP). These findings are consistent with the high TDF composition in SP (39.67%) compared to CL (32.99%) and KA (25.05%). Likewise, a significant increase in ash content (p < 0.05) was observed when more seaweed was added to the sausages, with SP having the most pronounced effect. Generally, the ash content in seaweed is high compared with other terrestrial plants, making it a better source of minerals [27].

3.2. Water Holding Capacity, Cooking Loss and Colour

The effects of adding seaweed on the water holding capacity (WHC), cooking loss, and the colour of the sausages are shown iLn

Table 4. Water holding capacity, cooking loss and the colour of the chicken sausage incorporated with seaweed.

Treatment	Water Holding Capacity (%)	Cooking Loss (%)	Colour
			Lightness (L*)	Redness (a*)	Yellowness (b*)
Control	8.86 ± 0.67 ab	12.22 ± 0.65 a	63.50 ± 1.53 a	0.84 ± 0.10 e	13.46 ± 0.20 ab
KA2	2.87 ± 0.81 fg	11.23 ± 0.96 ab	60.27 ± 2.05 b	0.99 ± 0.11 d	13.24 ± 0.25 ab
KA4	1.80 ± 0.20 gh	10.69 ± 0.09 b	57.62 ± 1.31 c	1.08 ± 1.32 cd	13.13 ± 0.41 ab
KA6	1.60 ± 0.22 h	9.79 ± 0.17 c	56.11 ± 1.30 c	1.21 ± 0.10 bce	12.93 ± 0.24 b
SP2	7.31 ± 1.37 bc	11.50 ± 0.06 a	42.86 ± 1.88 e	1.03 ± 0.12 c	11.95 ± 0.14 d
SP4	5.22 ± 0.61 de	9.54 ± 0.18 c	37.54 ± 1.44 f	1.34 ± 0.12 be	10.87 ± 0.32 d
SP6	4.69 ± 1.13 def	7.84 ± 0.41 d	33.53 ± 0.60 g	1.61 ± 0.07 a	10.82 ± 0.44 c
CL2	5.55 ± 0.51 cd	11.27 ± 0.08 a	45.93 ± 0.60 d	−4.17 ± 0.06 g	13.66 ± 0.36 b
CL4	3.75 ± 0.99 ef	6.51 ± 0.33 ef	39.00 ± 1.98 f	−4.15 ± 0.22 g	12.74 ± 0.20 cd
CL6	2.56 ± 0.39 g	6.15 ± 0.77 f	36.72 ± 0.94 f	−2.40 ± 0.11 f	11.48 ± 0.79 ab

Mean ± standard deviation in the same column with different superscript alphabets (^a–h) indicates there is a significant difference (p < 0.05). KA2, KA4, and KA6: Sausage with added 2, 4, and 6% of Kappaphycus alvarezii, SP2, SP4, and SP6: sausage with added 2, 4, and 6% of Sargassum polycystum, CL2, CL4, and CL6; sausage with added 2, 4, and 6% of Caulerpa lentilifa.

. The percentage of water loss decreased significantly as more seaweed was added to the sausages. The control sample lost the most water, followed closely by SP2. Sausages with KA lost less water, implying that KA has good water retaining ability. According to a previous study, there is a large amount of dietary fiber in seaweed, contributing to its high WHC [28]. This is also in agreement with another study that reported that adding soluble fiber from seaweed such as carrageenan improved water binding, gelling, thickening, and emulsion stability in muscle food [24]. The polysaccharide composition of the dietary fiber fractions is closely related to the water holding capacity; therefore, the type and amount of their polysaccharides affect the gelation process [29].

The good WHC contributed by seaweeds resulted in a lower cooking loss in the sausages. Cooking loss was calculated from differences in the weights of uncooked and cooked samples, expressed as the percentage of initial weight. When the sausages were formulated with seaweeds, there were significant improvements in the cooking loss compared to sausages without seaweed (p < 0.05). The control sample showed the highest cooking loss as seaweed fiber lowered the cooking loss due to its capacity to hold water and fat. Seaweed decreases the loss of fat and moisture during cooking and stabilizing emulsions [30].

Colour is one of the key parameters that determines the consumer acceptance of a product. Table 4 shows the lightness (L*), redness/greenness (a*), and yelowness/blueness (b*) of the sausage formulations. The results indicated that the inclusion of seaweed had altered the colour characteristics of chicken sausage. The chicken sausages darkened as more seaweed was added. The L* values of sausages with added KA seaweed decreased slightly compared to the SP- and CL-treated sausages. The SP6 sausage had the lowest L* value due to the brownish colour of the seaweed. The redness value (a*) of the chicken sausages with seaweed also increased. The CL-treated sausages had the lowest a* value, due to the green hue of the CL seaweed. In terms of yellowness (b*) values, there was no significant difference between the control sausage and the KA- treated sausages at all levels of inclusion (p < 0.05). However, the b* decreased significantly (p < 0.05) in SP- and CL-treated sausages. The higher the percentage of seaweed, the darker the colour of the chicken sausages. The phycoerythrin and phycocyanin compounds in seaweeds caused the colour changes in the chicken sausages (KA). These pigmentations overlap with other pigments such as chlorophyll and carotene beta [31]. Meanwhile, the reduction of lightness in the chicken sausages with SP was due to SP’s brown colour, brought upon by yellow pigments such as chlorophyll, phycopine, and xanthophyll [32]. Meanwhile, C. lentilifira (CL) contained starch, cellulose, xylan, and ionic polysaccharide consisting of sulphate group and uronic acid [28].

3.3. Texture

Table 5. Texture profile analysis of all sausage formulations.

Parameter	Seaweed Powder	KA	SP	CL
Hardness (N)	0%	23.24 ± 1.49 d	23.24 ± 1.49 d	23.24 ± 1.49 d
	2%	39.96 ± 1.77 cC	57.41 ± 3.95 bA	42.15 ± 1.96 aB
	4%	56.55 ± 1.89 bB	62.37 ± 2.68 bA	43.82 ± 6.49 aC
	6%	67.10 ± 1.72 aB	81.84 ± 9.12 aA	46.04 ± 6.90 aC
Cohesiveness	0%	0.66 ± 0.02 a	0.66 ± 0.02 a	0.66 ± 0.02 a
	2%	0.64 ± 0.01 aA	0.65 ± 0.00 aA	0.71 ± 0.01 aA
	4%	0.67 ± 0.02 aA	0.65 ± 0.00 aA	0.64 ± 0.04 aA
	6%	0.67 ± 0.01 aA	0.65 ± 0.00 aA	0.67 ± 0.11 aA
Springiness	0%	0.86 ± 0.09 a	0.86 ± 0.09 a	0.86 ± 0.09 a
	2%	0.91 ± 0.06 aA	0.86 ± 0.02 aA	0.88 ± 0.03 aA
	4%	0.91 ± 0.01 aA	0.82 ± 0.01 aA	0.87 ± 0.04 aA
	6%	0.89 ± 0.09 aA	0.86 ± 0.09 aA	0.87 ± 0.08 aA
Chewiness	0%	14.78 ± 3.14 d	14.78 ± 3.14 d	14.78 ± 3.14 d
	2%	21.23 ± 1.58 cC	34.99 ± 1.27 bA	26.94 ± 2.96 aB
	4%	34.33 ± 1.53 bA	32.84 ± 2.17 bA	25.07 ± 2.80 aB
	6%	39.67 ± 0.97 aB	42.72 ± 6.52 aA	26.10 ± 2.11 aC

Mean ± standard deviation in the same column with different superscript alphabets (^a–d) indicates there is a significant difference (p < 0.05) within the same cparameter. Mean ± standard deviation in the same row with different superscript alphabets (^A–C) indicates there are significant difference (p < 0.05). KA: Sausage with added Kappaphycus alvarezii, SP: sausage with added Sargassum polycystum, CL; sausage with added Caulerpa lentilifa.

presents the texture profile analysis of sausages with added seaweed. KA, SP, and CL significantly affected the textural properties of the sausages, specifically in terms of hardness and chewiness (p < 0.05). Hardness and chewiness increased with more addition of seaweed in the sausage formulation. Meanwhile, there were no significant difference in the cohesiveness and springiness parameters between the treatments (p < 0.05). The SP-treated sausages had the highest hardness value compared to other samples (p < 0.05).

These findings were in agreement with those reported by [33], who noted that sea tangle in pork patties caused an increase in its hardness. The authors of [34] also reported that different types and concentrations of edible seaweed improved the hardness of the emulsion meat system. However, the addition of high concentration of seaweed, notably the SP, adversely affected the hardness and chewiness of the sausages and led to declining sensorial acceptability. These results may be due to higher dietary fiber content in SP which enhanced the water holding capacity in meat, forming a hard and compact structure. Furthermore, the type of fiber and particle size of the added seaweed also affected the texture of the meat [35].

3.4. Sensory Characteristics

The sensory characteristics of the chicken sausages incorporated with the seaweeds KA, SP, and CL are shown in

Table 6. The sensory assessment of chicken sausage with seaweed.

Sensory Assessement	Seaweed Powder Percentage	KA	SP	CL
Shape	0%	6.41 ± 0.71 ab	6.41 ± 0.71 a	6.41 ± 0.71 a
	2%	6.69 ± 0.89 aA	5.60 ± 0.64 bA	4.86 ± 0.55 bB
	4%	6.21 ± 1.00 abA	4.44 ± 1.23 cB	4.68 ± 0.67 bB
	6%	6.14 ± 1.03 bA	3.85 ± 1.22 dB	3.88 ± 0.98 cB
Colour	0%	6.24 ± 0.74 ab	6.24 ± 0.74 a	6.24 ± 0.74 a
	2%	6.58 ± 0.86 aA	4.94 ± 0.90 bB	4.23 ± 0.54 bB
	4%	6.08 ± 1.04 abA	3.74 ± 1.19 cB	4.21 ± 0.58 bB
	6%	5.89 ± 1.09 Ba	3.60 ± 1.37 cB	3.38 ± 0.74 cB
Aroma	0%	6.26 ± 0.72 ab	6.26 ± 0.72 a	6.26 ± 0.72 a
	2%	6.42 ± 0.92 aA	6.57 ± 0.89 aA	4.42 ± 0.48 bB
	4%	6.10 ± 1.15 abA	4.43 ± 1.43 bB	4.25 ± 0.56 bB
	6%	5.71 ± 0.99 bA	4.07 ± 1.56 bA	3.61 ± 0.93 cA
Taste	0%	6.00 ± 0.71 ab	6.00 ± 0.71 a	6.00 ± 0.71 a
	2%	6.37 ± 0.87 aA	6.05 ± 0.77 aA	4.62 ± 0.70 bB
	4%	5.58 ± 1.01 bA	4.68 ± 0.98 bB	4.42 ± 0.83 bB
	6%	5.88 ± 0.94 abA	3.04 ± 1.07 cB	3.68 ± 0.79 cB
Hardness	0%	6.05 ± 0.63 ab	6.05 ± 0.63 a	6.05 ± 0.63 a
	2%	6.22 ± 0.75 aA	6.40 ± 0.55 aA	4.56 ± 0.65 bB
	4%	5.61 ± 0.98 bcA	4.90 ± 0.96 bA	4.42 ± 0.72 bB
	6%	5.39 ± 0.99 cA	3.50 ± 0.88 cB	3.72 ± 0.78 cB
Juiciness	0%	5.90 ± 0.64 ab	5.90 ± 0.64 a	5.90 ± 0.64 a
	2%	6.20 ± 0.75 aA	4.60 ± 0.47 bB	4.58 ± 0.64 bB
	4%	5.44 ± 0.99 bA	4.63 ± 0.92 bA	4.46 ± 0.68 bA
	6%	5.57 ± 0.93 bA	3.01 ± 0.92 cB	3.79 ± 0.89 cB
Overall	0%	6.26 ± 0.67 ab	6.26 ± 0.67 a	6.26 ± 0.67 a
	2%	6.45 ± 0.88 aA	5.92 ± 0.60 aAB	4.94 ± 0.64 bB
	4%	5.81 ± 1.00 bcA	5.32 ± 0.50 bB	4.82 ± 0.68 bB
	6%	5.65 ± 0.95 cA	3.46 ± 1.10 cB	4.00 ± 0.86 cB

Mean ± standard deviation in the same column with different superscript alphabets (^a–d) indicates there is a significant difference (p < 0.05) of sensory assessment. Mean ± standard deviation in the same row with different superscript alphabets (^A,B) indicates there are significant difference (p < 0.05). KA: Sausage with added Kappaphycus alvarezii, SP: sausage with added Sargassum polycystum, CL; sausage with added Caulerpa lentilifa.

. In general, the addition of seaweed reduced the sensory acceptance of the chicken sausages in terms of appearance, colour, aroma, taste, hardness, and overall acceptance. Sensory test results showed that KA had higher score values for all sensory attributes compared to SP and CL. The addition of KA at 2% and 4% did not cause a significant difference in appearance and colour of the sausage compared to the control sample (p < 0.05). The addition of SP and CL in chicken sausage lowered the acceptance score for appearance and colour attributes (p < 0.05). The panellists accepted the aroma and taste of chicken sausages with KA (p < 0.05), accepted the aroma and taste of only the sausages with 2% SP, and did not accept the aroma and taste of any chicken sausages with added CL at any level. For the attributes of hardness and juiciness, the addition of up to 4% KA showed no significant difference compared to the control sample (p < 0.05). Sensory results showed that for overall acceptance, the addition of KA up to 6% and SP 4% into the chicken sausage was acceptable by the panellists (p < 0.05). The addition of CL in the chicken sausage was not acceptable to the panellists, due to the taste and aroma of CL which the panellists probably disliked. This result may be compared to that of another study, which reported that consumers preferred the control sample more than chicken steak supplemented with the seaweed Himanthalia elongate.

3.5. Total Phenolic Content (TPC) and Antioxidant Activity

The total phenolic contents (TPC) of the chicken sausage formulations are presented in

Table 7. Total phenolic content of all chicken sausage formulations.

Seaweed Powder	KA	SP	CL
0%	0.15 ± 0.26 c	0.15 ± 0.26 c	0.15 ± 0.26 d
2%	1.92 ± 0.04 bA	1.57 ± 0.00 bA	1.98 ± 0.13 cA
4%	3.59 ± 0.65 aA	3.44 ± 0.15 aA	4.27 ± 0.00 bA
6%	4.13 ± 0.79 aB	3.59 ± 0.07 aC	6.65 ± 0.09 aA

Mean ± standard deviation in the same column with different superscript alphabets (^a–d) indicates there is a significant difference (p < 0.05). Mean ± standard deviation in the same row with different superscript alphabets (^A–C) indicates there are significant differences (p < 0.05). KA: Sausage with added Kappaphycus alvarezii, SP: sausage with added Sargassum polycystum, CL; sausage with added Caulerpa lentilifira.

. Generally, the TPC in the treated formulations were higher (p < 0.05) than in the control sample. At 2% and 4% of seaweed added, there were no significant differences among the three types of seaweed (p < 0.05). However, at 6% of seaweed added, C. lentilifira (CL) sausages indicated the highest TPC value compared to K. alvarezii (KA) and S. polycystum (SP). This was due to CL (7.18 ± 0.66 mg GAE/g) containing more phenolic compounds than KA (1.65 ± 0.06 mg GAE/g) and SP (2.25 ± 0.06 mg GAE/g) as shown in Table 1. In this study, the control sample had the lowest TPC (0.15 mg GAE/g), while the sausages supplemented with seaweed had TPC values between 1.57 mg GAE/g and 6.65 mg GAE/g. The 6% CL sausage samples had the highest TPC value of all the sausages. Additionally, high pressure is also one of the reasons for the deterioration of phenolic compounds such as catechin [19]. Seaweeds employ their phenolic compounds to overcome the oxidative stress caused by their harsh native environment. Other than inter-species differences, the phenolic content in seaweed could be influenced by seasons, with TPC being higher during the summer [32].

The DPPH assay is used to ascertain antioxidant activities through a mechanism in which antioxidants act to inhibit lipid oxidation, scavenging DPPH radical, and therefore determine free radical scavenging capacity. The method is widely used due to the relatively short time required for the analysis [36]. The DPPH free radical method is an antioxidant assay based on electron transfer that produces a violet solution in ethanol [37]. Figure 1 presents the DPPH scavenging activity of the sausages with added seaweeds. The TPC in the control sample was low. The DPPH assay result increased as more seaweed were added into the chicken sausages (p < 0.05). Chicken sausages with 6% C. lentilifira (CL) showed the highest DPPH scavenging activity (50%), while 2% CL sausages had the lowest antioxidant activity of all seaweed sausages. The DPPH scavenging activity was more active in the C. lentilifira (CL) sausage samples compared to the other formulations. This could be due to its high detectable phenols as shown in the TPC value result, which indicated that CL has the highest total phenolic compound (Table 4). The phenolic compounds are a large and diverse molecule group. The group includes a variety of aromatic secondary metabolite families in plants [38]. The major active phenolic compounds in different seaweed are fucoxanthin and phlorotannins [26].

3.6. Lipid Oxidation of Sausage during Storage

Lipid oxidation is a major cause of deterioration in the quality of meat and meat products [39]. A TBARS test measures the level of malondialdehyde (MDA) present in a meat product. It has been reported that rancidity could be detected at 1.0–2.0 mg malonaldehyde/kg TBA value in chicken. However, the consumption limit of malonaldehyde is 7–8 mg/kg [40]. The sensory results showed that chicken sausages with 2% seaweed for the three types of seaweed, and 4% K. alvarezii are the most preferred by the panellists. Therefore, these samples were further studied for lipid oxidation during storage at 4 °C for 28 days. Based on the finding presented in Figure 2, the malonaldehyde content measured in this study ranged from 0.04 mg MDA/kg to 3.98 mg MDA/kg. Generally, the oxidation of lipid in the chicken sausages increased from day 0 to day 14, which was in the range of 0.04 mg MDA/kg to 2.82 mg MDA/kg. After day 14, lipid oxidation continued to increase until day 28 (2.82 mg MDA/kg to 3.98 mg MDA/kg). The results showed that the control sample had the highest TBARS value compared to other seaweed-added samples throughout the storage period, especially on day 21.

The decrease of TBARS value was due to the high antioxidant content of the seaweed incorporated into chicken sausages [38]. According to [28], the addition of H. elongata seaweed to beef patties lowered its TBARS value, and they claimed that it was due to the seaweed conferring a protective effect against lipid oxidation. A study on the addition of K. alvarezii on the lipid oxidation of mechanically deboned chicken meat sausage by [19] also found a reduction in TBARS value as the concentration of K. alvarezii increased. This was due to the antioxidant activity present in the seaweed.

4. Conclusions

This study showed that the inclusion of seaweed improved the water holding capacity of chicken sausages, leading to reduced weight loss during cooking. Seaweed also had potential health benefits by adding to the dietary fiber and mineral content of the sausage. However, the added seaweed modified the sensory and textural aspects of the final product. Chicken sausages incorporated with up to 4% of KA and 2% of SP were found to be organoleptically acceptable and texturally comparable to the control samples. Furthermore, the TPC of the seaweed acted as an antioxidant, which helped abate the oxidation of the lipid in the chicken sausage. KA and SP may be included in meat products for their benefits in enhancing functional characteristics and nutritional composition.