Next Article in Journal
The Spatiotemporal Differentiation Characteristics and Driving Forces of Carbon Emissions from Major Livestock Farming in the Shaanxi–Gansu–Ningxia Region
Previous Article in Journal
Fibrolytic Enzymes and Lactic Acid Bacteria Improve the Ensiling Characteristics of Ramie and Elephant Grass Mixed Silage
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Agriculture
Volume 14
Issue 10
10.3390/agriculture14101747
agriculture-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Utilization of Flours Derived from the Waste from the Frozen Vegetable Industry for Bakery Product Production

by
Miguel A. Gallardo
,
María Esther Martínez-Navarro
,
Manuel Álvarez-Ortí
and
José E. Pardo
*
Higher Technical School of Agricultural and Forestry Engineering and Biotechnology, University of Castilla-La Mancha, Campus Universitario, s/n, 02071 Albacete, Spain
*
Author to whom correspondence should be addressed.
Agriculture 2024, 14(10), 1747; https://doi.org/10.3390/agriculture14101747
Submission received: 3 September 2024 / Revised: 30 September 2024 / Accepted: 2 October 2024 / Published: 3 October 2024
(This article belongs to the Section Agricultural Product Quality and Safety)
Browse Figures
Versions Notes

Abstract

:
Currently, the agri-food industry faces a significant challenge in reducing food waste in line with circular economy principles. In this context, the frozen vegetables industry rejects products that do not meet consumers’ appearance standards, leading to a waste of vegetables that could be reincorporated into the food chain. Thus, waste generated from broccoli, cauliflower, and peas in the last selection stages of a frozen vegetable industry manufacturer were collected, dehydrated, and transformed into flour. These flours were used to replace 50% of the wheat flour in a basic bakery product, using a baked dough made only with flour and water, and analyzed from physical, nutritional, and sensory perspectives. The doughs showed slight changes in texture, with increased hardness values and reduced cohesiveness, making them more difficult to handle, as well as changes in color due to the incorporation of vegetable pigments. However, from a nutritional perspective, these products were enriched in protein, with values that reached up to 20.88% in the sample made with broccoli flour, and dietary fiber, with an increase from 0.67% obtained in the control sample to 6.00% in the sample made with pea flour and to over 8 in the samples made with broccoli and cauliflower. This was accompanied by a reduction in total carbohydrates, leading to similar energy values (around 380 kcal/100 g dm). Furthermore, the content in total phenolic compounds and antioxidant activity were increased, especially when flours from the Brassica species were used. From the sensory point of view, all the samples made with vegetable flours received positive evaluations, even higher than the control sample when smell or taste was evaluated. In this regard, the samples made with cauliflower flour stood out when the taste was evaluated, reaching values above three on a scale where the maximum value was four. All of these results demonstrate that using these wasted vegetables can be a good alternative for improving the nutritional properties of basic bakery products.

1. Introduction

One of the main challenges currently faced by the agri-food industry is the valorization of food waste to achieve sustainable development through the comprehensive use of raw materials [1]. In this sense, reducing food waste has become a pressing demand of society in recent decades and it has raised the imperative of making better use of the byproducts and waste generated within the agri-food industry. It is estimated that the agri-food sector discards approximately 1.3 billion tons of food each year worldwide [2], equivalent to roughly one-third of the food produced for human consumption. This not only has significant economic repercussions but also poses substantial environmental sustainability and global food security concerns [3,4]. Food waste can occur at various stages of the supply chain, from production to final consumption, often due to products not meeting stringent quality standards and food safety regulations. Surprisingly, many of these discarded products remain perfectly acceptable for consumption and contain valuable bioactive compounds that contribute to a healthy diet.
Within the agri-food sector, the frozen vegetable industry plays an important role. Freezing vegetables helps preserve their nutrients [5,6], so that they can be consumed year-round. Additionally, freezing vegetables contributes to reducing food waste by allowing the utilization of production surpluses and making vegetables more accessible, especially in regions where certain types of vegetables are not produced. In Spain, frozen vegetable production has experienced steady growth in recent years, reaching around 600,000 tons in 2019, and highlighting the importance of this sector in the Spanish economy. However, in many vegetable freezing companies, during the final stages of the selection process, vegetables failing to meet the stipulated customer specifications, in terms of the shape or color, are rejected. These vegetables have already undergone the freezing procedure and, in the process, have retained their nutritional integrity, thereby containing a substantial quantity of nutrients that can potentially be reintegrated into the food supply chain.
Cruciferous vegetables such as broccoli and cauliflower are packed with nutrients, including fiber, vitamins, and essential minerals. Broccoli is rich in bioactive compounds including sulforaphane and isothiocyanates, known for their anti-inflammatory, antioxidant, and anticancer properties, which potentially guards against chronic diseases such as cancer and cardiovascular issues [7]. Additionally, broccoli contains the essential vitamin C, which acts as an antioxidant and is vital for immune function and collagen formation. Cauliflower, another cruciferous vegetable, offers a versatile cooking option and is a good source of vitamins, minerals, and dietary fiber. It is especially high in vitamin C, folic acid, vitamin K, and potassium, while also containing beneficial bioactive compounds including glucosinolates and flavonoids, which have been studied for their potential to prevent chronic diseases and combat inflammation [8]. Peas, on the other hand, are rich in nutrients and bioactive compounds including flavonoids and carotenoids, known for their antioxidant and anti-inflammatory properties, potentially guarding against conditions such as diabetes, cardiovascular diseases, and cancer [9].
The use of residue from fruits and vegetables for animal feed or biofuel production has been suggested [10,11]. However, with regards to the waste generated within the vegetable freezing industry, their nutrient retention profile makes them suitable for reintroduction into the food chain, given the numerous health benefits associated with their consumption. This can be achieved through the process of dehydration and conversion into flour, which can then be used in the production of basic products such as bakery goods. This approach aims to fulfill society’s objectives regarding food security and the principles of a circular economy for sustainable food production by valorizing waste materials.
In addition, bakery products are typically crafted from doughs primarily composed of wheat flour, due to the special viscoelastic properties provided by their gluten network [12]. Gluten in bakery products provides structure and gas retention, allowing the products to rise and have a fluffy texture. It also enhances elasticity and moisture retention, extending the freshness of baked goods. Nevertheless, the nutritional composition of wheat flour, which is characterized by its high carbohydrate content and relatively low levels of proteins, fiber, and minerals, suggests the importance of substituting or supplementing it with other ingredients to enhance the nutritional qualities of the final products [13].
In accordance with the aforementioned considerations, the primary goal of this study is to assess the utilization of waste generated during the final selection stage of a vegetable freezing industry manufacturer, specifically from broccoli, cauliflower, and pea processing, for the production of flour. Furthermore, we aim to explore its potential as an ingredient in the formulation of basic doughs for bakery products, while also evaluating the nutritional enhancements it can offer.

2. Materials and Methods

2.1. Raw Materials and Production of Flours and Dough

Samples of broccoli, cauliflower, and peas were collected from the waste generated at the final selection stage by the industry manufacturer Ultracongelados Campo Verde (Albacete, Spain). These samples had underwent the blanching and freezing process but were discarded because they did not meet the quality criteria established for the final product (defects in color, shape, or size).
The samples were subjected to hot air drying at a temperature of 60 °C until a constant humidity content was achieved. In this sense, the moisture was measured at 1 h intervals during the drying process with the moisture balance Ohaus MB45 (Ohaus Corporation, Parsippany, NJ, USA). The final humidity was measured by drying the samples in an oven at 105 °C overnight. The values of humidity measured at the end of the dehydration process were as follows: 4.43 ± 0.41% for broccoli, 3.05 ± 0.58% for cauliflower, and 7.73 ± 0.88% for peas. These values were obtained after a drying time frame of 6 to 7 h. Subsequently, the dehydrated samples were ground and sieved to produce flours with a particle size less than 1 mm.
The flours were used to make a basic dough, only using flour, water, and salt (Table 1). In this sense, to evaluate the differences with the traditional products, a control dough was made with wheat flour acquired in local markets, salt, and water. The control recipe consisted of 200 g of wheat flour, 5 g of salt, and 120 mL of water. The broccoli, cauliflower, and pea flours were used to partially replace (50%) the wheat flour. In these cases, a different amount of water was added to obtain a manageable dough, and with characteristics similar to the control. The dough was stretched to obtain a 3 mm sheet and baked at 180 °C for 17 min. The product that was made consisted of a dry and hard bread, similar to a biscuit or a cracker (Figure 1).

2.2. Physical Measurements

The color was measured during the whole process, from the dehydration of raw materials to the final product. Thus, the color of the dehydrated peas, broccoli, and cauliflower, the flours, the different doughs made, and the baked products was measured by reflection in 5 different points with a Minolta CR-300 colorimeter (Minolta Camera Co., Ltd., Osaka, Japan) and the values of lightness (L*), red-green component (a*), and yellow-blue component (b*) were annotated, according to the protocols of the International Commission on Illumination.
Texture profile analysis (TPA) was employed to assess the textural characteristics of the different doughs (hardness, cohesiveness, springiness, and adhesiveness). The assessment was conducted using a TA-TX Plus instrument (Stable Micro Systems, Godalming, UK). Three samples of 20 g for each type of dough were examined.

2.3. Proximate Analysis

The proximate analysis was conducted for the baked product, to determine the content of ash, protein, fats, and carbohydrates, and the total energy value. To determine the ash content, samples were incinerated at 550 °C until a constant weight was achieved [14]. For protein content, the Kjeldahl method was employed, involving the multiplication of total nitrogen content by a conversion factor of 6.25 [15]. Crude fat was extracted using the filter bag technique with an Ankom XT10 extractor (ANKOM Technology, Macedon, NY, USA) [16].
On the other hand, crude fiber content results were obtained using the Weende technique adapted for the filter bag technique, as outlined by ANKOM [15]. This method involves determining the organic residue through digestion with sodium hydroxide and sulfuric acid solutions in an Ankom 220 fiber analyzer (ANKOM Technology, Macedon, NY, USA).
Total carbohydrate content was calculated by subtracting the sum of protein, fat, water, and ash from the total carbohydrate content [17]. Finally, the total energy was calculated based on Atwater values, which are 9 kcal/g for fat, 4 kcal/g for protein, and 4 kcal/g for carbohydrates, using 100 g of the sample as the basis [18].

2.4. Total Phenolics and Antioxidant Capacity

The total phenol content (TPC) was measured by the Folin-Ciocalteau method in the flours and in the baked products to evaluate the changes produced during the thermal treatment applied in the baking process. Thus, 2 g of ground flour or baked product was extracted with 20 mL of methanol at room temperature, in the dark, overnight. Then, 50 μL of the extract was mixed with 250 µL of the Folin-Ciocalteau reagent and 750 µL of 20% Na2CO3 (w/v) in a final volume of 5 mL. The mix was incubated in the dark. After 30 min, the absorbance was measured at 765 nm. A calibration curve using gallic acid was prepared. All samples were analyzed in triplicate.
To evaluate the antioxidant capacity of the flour and the baked products, the 2,2-diphenyl-1-picrylhydrazyl radical inhibition (DPPH) method was used. First, DPPH solution (6 × 10−5 mol/L in ethanol) was freshly prepared. Then, 30 μL of the same extract, prepared for TPC, was mixed with 2970 μL of the DPPH solution. After 1 h, the absorbance at 517 nm was measured. The results were expressed in % inhibition. All determinations were conducted in triplicate.

2.5. Sensory Evaluation

An affective test was conducted to evaluate consumer acceptance of the samples through a 9-point verbal hedonic scale, ranging from −4 (extremely dislike) to +4 (extremely like). A total of 100 consumer judges were asked to rate their preference for external appearance, texture, smell, and taste in the control sample made with wheat flour and the samples made with pea, broccoli, and cauliflower flours. The consumer judges were selected from the students and staff of the Higher Technical School of Agricultural Engineering and Forestry and Biotechnology in Albacete, with the sole requirement that they were consumers of this type of product, ensuring sufficient diversity in both gender and age. A total of 100 consumer judges is considered an ideal number to ensure diverse and statistically significant results, since they represent the target population, and provide varied preferences to capture a broad range of opinions for accurate product evaluation. In addition, this sample size balances cost and time efficiency. The tasting sessions were conducted during June 2024.
The external appearance was evaluated through a visual examination of the baked products, presented as shown in Figure 1. On the other hand, to evaluate the texture, smell, and taste, a traditional recipe was prepared with these products (“Gazpachos manchegos”), to which tomato, paprika, and potato were added and boiled in water for 20 min. The samples were cooked before consumption, as they consist of a dry, baked dough that requires boiling to soften and integrate with the other ingredients.

2.6. Statistical Analysis

Statistical differences were estimated (p < 0.05) from an analysis of variance (ANOVA) and a Duncan test. All statistical data and analysis were carried out using the SPSS program (IBM, Armonk, NY, USA), version 23.0 for Windows.

3. Results and Discussion

3.1. Physical Analysis

The addition of flours that replaced the traditionally used wheat flour in bakery products led to changes in the physical properties of the food. These changes were reflected in the color, generally increasing its intensity due to the pigments present in the products used to make the flours, and in the texture, where the replacement of wheat flour generally resulted in products that were firmer, less elastic, and less cohesive due to the substitution of gluten [19].
Color plays a crucial role in consumers’ food preferences and can determine its acceptance or rejection [20]. However, color is also important because it is related to the presence of certain pigments that may have bioactive properties [21]. For example, it has been described that chlorophyl, responsible for the green color, and abundant in many vegetables such as broccoli or peas, can exhibit many health benefits, including antioxidant, anti-cancer, antimutagenic, and anti-inflammatory processes [22]. The replacement of ingredients or the processing of products may cause changes in the color of foods, either due to the addition of new pigments present in the new ingredients or the degradation of these due to thermal or oxidative processes. Therefore, color measurement of foods may provide data about the presence and evolution of these pigments when some ingredients are replaced.
When the thermal treatments were applied to the broccoli and peas, a change in color was observed. When high temperatures are applied, chlorophyl is degraded into pheophytin, with an olive-green color, which is converted into pheophorbide, a stable component with a brown color that accumulates during the process [21]. Therefore, the flour of broccoli and pea showed an increase in the values of the a* component, leading to a decrease in the greenish tones (Figure 2).
In the case of cauliflower where is no chlorophyll, the initial color was white, with very low values of both components, but then turned brown-yellow when the thermal treatments were applied (by dehydration and baking). The final baked product showed positive values especially for the b* component, which indicated yellowish tones. This change of color could be produced by the oxidation of flavonoids, which may lead even to a black color in cases of extreme oxidation.
Texture is another parameter that is highly sensitive to substantial alterations when ingredient substitutions are made, influenced by their rheological attributes. In this context, texture analysis of the dough is crucial, since the dough serves as an intermediate product between the flour and the baked product, and its characteristics can significantly affect both the processability and the final product quality [23]. The replacement of ingredients may lead to increased firmness, reduced porosity, and create a more compact, less elastic structure [24]. Gluten plays an important role in dough formation. It is a protein complex found in wheat flour, which is essential for developing the structure and elasticity needed to produce high-quality bread and other baked products [25]. It is well known for its viscoelastic properties, with the capacity to confer elasticity and cohesiveness to the dough, primarily through a network formation that trap the gas contained within. When gluten was partially replaced, a harder and less cohesive dough was observed (Table 2). The dough prepared using broccoli flour exhibited elevated hardness, implying increased resistance to handling and kneading. Additionally, doughs incorporating vegetable waste flours, in general, displayed reduced cohesiveness, potentially resulting in fractures during the kneading and stretching processes, leading to a fragmented final product.
Finally, when the dough was supplemented with 50% of the frozen vegetable waste flours, the adhesiveness values were higher (Table 2), which may lead to more difficult handling during the kneading and stretching of the dough.

3.2. Proximate Analysis

White wheat bread and similar products are globally consumed as a source of energy primarily derived from complex carbohydrates, notably starch. Nevertheless, from a nutritional perspective, these products demonstrate deficiencies in essential nutrients such as proteins and dietary fiber. Consequently, ongoing trials aim to fortify products with novel ingredients rich in these nutrients, generally derived from by-products or residues of the food industry, to enhance the nutritional content of these bakery products [26,27,28].
In this case, when 50% of the wheat flour was replaced with the flours from broccoli, cauliflower, and pea, increases in the content of protein and crude fiber was observed, coupled with a decrease in the total carbohydrate content (Table 3). Brassica species-derived flours are considered a good source of protein to be used in the production of novel foods [29]. For example, frozen broccoli florets, which are subjected to a previous blanching process, still contain around 30% of protein [30]. In addition, previous studies have also shown that peas are another potential ingredient to increase the nutritional characteristics of bread or other bakery products, since pea flour contains about 21% of protein and 15.5% of dietary fiber [31]. It also contributed to the increase in protein content to 15.94% when the bread was supplemented with 50% pea flour.
Dietary fiber is a crucial nutrient with both functional and nutritional significance. Higher levels of dietary fiber are associated with health benefits, primarily related to their positive impact on gut microbiota, which contributes to the production of metabolites such as short-chain fatty acids and peptides [32]. The fiber content in bread increases significantly when the dough is supplemented with vegetable flours, reaching values of 8.13 and 8.58 when broccoli and cauliflower flours are used (Table 3). These vegetables are naturally rich in fiber and when they are dried and converted into flour [33,34]. On the other hand, although pea fiber content is lower compared to Brassica species, using pea flour also resulted in fiber-enriched bread, with values significantly higher than bread made exclusively with wheat flour. In addition, a high fiber content may confer water holding capacity to food formulations. Hence, it is necessary to add a larger quantity of water to the dough mixture to achieve a manageable consistency, allowing it to be kneaded in a manner similar to dough made exclusively with wheat flour.
Finally, the energy value did not exhibit significant differences as the reduction in total carbohydrates was replaced by higher protein content in the baked products supplemented with vegetable flours.

3.3. Total Phenolics and Antioxidant Capacity

Although the primary objective of this study was not to analyze the antioxidant capacity of these products, as thermal treatments can significantly diminish this parameter, the results for phenolic compound content and DPPH radical scavenging activity were included to provide an initial assessment of their potential changes. Brassica species contain a wide range of phytochemicals with health promoting activities, including phenolic compounds with antioxidant activity [35,36]. This content was reflected in the composition of the flour made with dehydrated broccoli and cauliflower wastes, which presented values of 566.22 and 370.17 mg of gallic acid equivalents (GAE)/100 g, respectively (Figure 3). This content was much higher than the fresh product since the dehydration process eliminated the water content and consequently increased the concentration of the rest of compounds.
A reduction in the content of total phenolic compounds was observed in the baked products, although a significant amount of these remained in the final product, especially in the cauliflower, but also in the broccoli and pea products. The phenolic compounds and the antioxidant capacity of a bread product containing 50% vegetable flour was inherently lower than that of the pure vegetable flour due to the dilution of antioxidant compounds. Specifically, the total antioxidant activity per 100 g of product was reduced because only half of the formulation comprised of vegetable-derived ingredients, which are rich in bioactive compounds. Consequently, the concentration of antioxidants, such as phenolic compounds and isothiocyanates, was diminished in the final products. However, when the product made with broccoli flour was considered, a decrease of more than 50% was observed, and may be attributed to the heat-induced degradation of thermolabile compounds, such as phenolics and isothiocyanates, which are sensitive to prolonged exposure to high temperatures.
The vegetable freezing process is carried out immediately after harvesting, which helps to preserve and keep all of its compounds intact. Although the vegetables generally undergo a prior blanching process, which is a mild heat treatment that affects, to a small extent, all of those bioactive compounds that may have beneficial health activities. Simultaneously, the blanching process inactivates enzymes that may be related to oxidation, thus preventing alterations from occurring during storage. The waste eliminated in the final stages in the selection of frozen vegetables has undergone this entire process, which is why they retain these compounds, often in better condition than fresh foods, which can then undergo oxidation processes during storage.
When the antioxidant capacity was analyzed in the flour and in the baked products by the DPPH method, a similar behavior to the phenolic compounds was observed, since the products from broccoli and cauliflower showed the highest values (Figure 4). In addition to phenolic compounds, Brassica vegetables contain other antioxidant phytochemicals with potential health benefits in chemoprevention, neuroprotection, and metabolic syndrome treatment [37]. This is the case with isothiocyanates, metabolites that originated from the hydrolysis of glucosinolates, which are found almost exclusively in the Brassicacea family of vegetables [38,39]. The presence of these compounds may be the responsible for the high antioxidant capacity observed in broccoli and cauliflower flour, which was significantly greater than that observed in pea or wheat flour.
A decrease in the antioxidant capacity was observed in the final baked products, which, similar to the case of the phenolic compounds, could be attributed to the product formulation that included only 50% of the vegetable flour, as well as to the thermal treatment itself that degrades certain thermosensitive antioxidant compounds. However, significant antioxidant activity still remained in the baked products when they were made from broccoli and cauliflower flours. As with the phenolic compounds, the decrease in antioxidant capacity was greater in broccoli than in cauliflower. In relation to the pea, the antioxidant activity was lower in the flour, and it was practically lost during baking, resulting in final values very similar to those observed in the product made from wheat flour.

3.4. Sensory Evaluation

The final step to evaluate a product, where the main ingredients have been replaced, is to perform a sensory analysis to evaluate consumers’ preferences, and check that the incorporation of the new ingredients do not affect the product sensory attributes. In this regard, sensory analysis is crucial for evaluating product quality and consumer acceptability in bakery items, as attributes such as color, flavor, and texture significantly influence initial consumer impressions and their likelihood of repurchase [40] (Figure 5).
In this case, an affective test through a 9-point verbal hedonic scale was used, which is a widely used method to assess consumer acceptance of foods due to its simplicity and the ease of understanding and use by participants [41]. This scale provides quantitative data that offers insights into both the degree of liking and specific product attributes, ensuring consistent and reliable results. To determine the degree of liking for these products, the external appearance, smell, texture, and taste were analyzed.
The external appearance of the baked products may determine first impressions and consumer expectations, influencing the willingness to try the product. The results showed, in general, positive evaluations (above zero), which indicated that these were products appreciated by consumers who showed their willingness to purchase and try them.
The only exception was when the external appearance of the broccoli sample was evaluated, which showed an average value slightly below zero, likely due to the green-brown color resulting from the oxidation of chlorophyll during baking. This effect was not shown for the pea sample, which maintained an attractive green color even when the thermal treatment of baking had been applied, and was reflected in the highest values when the external appearance was analyzed.
The main differences were found when the texture of the cooked samples was evaluated, since the samples using broccoli and pea showed lower average values. In this sense, the substitution of the wheat flour by other vegetable flours resulted in harder and less cohesive samples that were noticed by the consumer judges, although this effect was not observed for the cauliflower sample, with similar values compared to the control sample.
Finally, when the taste was evaluated, all of the samples obtained values above two, which meant that all of them were greatly appreciated by consumers. For this characteristic, the cauliflower sample stood out, reaching values above three. In this regard, the results were very positive, as consumers generally showed a preference for bakery products made with refined flours and low fiber content [42].

4. Conclusions

The waste obtained from the last selection stages of the frozen vegetable industries, discarded due to vegetables that do not meet external appearance requirements due to the size, form, or color, can be dehydrated and transformed into flour and incorporated into the formulation of bakery products.
These flours can produce significant changes in the physical parameters of the dough since they give rise to harder and less cohesive doughs that can be somewhat more difficult to knead and stretch. However, the replacement of wheat flour by broccoli, cauliflower, and pea flours contributed to increased nutritional value of the baked products, since the content of protein or dietary fiber were increased. In addition, the inclusion of these flours produced an increase in the antioxidant compounds of the bakery products, such as phenolic compounds, especially when broccoli or cauliflower were used. These increases in antioxidant compounds were reflected in the increased antioxidant capacity found in the bakery products made from vegetable flours, despite the thermal treatment applied during the baking process.
The sensory analysis revealed that, despite some variations in the external appearance and texture, the overall consumer acceptance of the products with replaced main ingredients was positive. Textural differences were noted, particularly in the broccoli and pea samples, which were perceived as harder and less cohesive. However, these variations did not substantially affect overall consumer acceptance, as all samples received positive ratings for taste, with the cauliflower sample standing out as particularly well-liked. These findings suggest that while ingredient substitution can impact certain sensory attributes, the products remain generally well-received by consumers.

Author Contributions

Conceptualization, M.A.G. and M.Á.-O.; Methodology, M.E.M.-N.; Validation, M.A.G. and M.Á.-O.; Formal analysis, M.E.M.-N.; Investigation, M.A.G. and M.E.M.-N.; Resources, J.E.P. and M.Á.-O.; Writing—original draft preparation, M.A.G. and M.Á.-O.; Writing—review and editing, M.Á.-O.; Visualization, M.Á.-O.; Supervision, J.E.P. and M.Á.-O.; Project administration, M.Á.-O.; Funding acquisition, M.Á.-O. and J.E.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Cátedra de Economía Circular from the University of Castilla-La Mancha, through the internal call for allocation of funds for research projects in collaboration with an observer promoting entity, year 2023, and the University of Castilla-La Mancha through the call for Plans for the Generation of Transfer and Collaborative Transfer Projects, co-financed by the European Regional Development Fund FEDER (2024-TRAN-36429).

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee at the University of Castilla-La Mancha (protocol code CEIS-710502-Z0D6, 24/10/2023).

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Acknowledgments

The authors would like to thank the company Ultracongelados Campo Verde for providing the samples of frozen vegetable waste used in this study.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Girotto, F.; Alibardi, L.; Cossu, R. Food waste generation and industrial uses: A review. Waste Manag. 2015, 45, 32–41. [Google Scholar] [CrossRef] [PubMed]
  2. FAO. The State of Food and Agriculture 2019: Moving Forward on Food Loss and Waste Reduction; FAO: Roma, Italy, 2019. [Google Scholar]
  3. Godfray, H.C.J.; Beddington, J.R.; Crute, I.R.; Haddad, L.; Lawrence, D.; Muir, J.F.; Pretty, J.; Robinson, S.; Thomas, S.M.; Toulmin, C. Food security: The challenge of feeding 9 billion people. Science 2010, 327, 812–818. [Google Scholar] [CrossRef] [PubMed]
  4. Kummu, M.; de Moel, H.; Porkka, M.; Siebert, S.; Varis, O.; Ward, P.J. Lost food, wasted resources: Global food supply chain losses and their impacts on freshwater, cropland, and fertiliser use. Sci. Total Environ. 2012, 438, 477–489. [Google Scholar] [CrossRef] [PubMed]
  5. Bouzari, A.; Holstege, D.; Barrett, D.M. Vitamin Retention in Eight Fruits and Vegetables: A Comparison of Refrigerated and Frozen Storage. J. Agric. Food Chem. 2015, 63, 957–962. [Google Scholar] [CrossRef]
  6. Martínez, S.; Armesto, J.; Gómez-Limia, L.; Carballo, J. Impact of processing and storage on the nutritional and sensory properties and bioactive components of Brassica spp. A review. Food Chem. 2020, 313, 126065. [Google Scholar] [CrossRef]
  7. Wu, L.; Noyan Ashraf, M.H.; Facci, M.; Wang, R.; Paterson, P.G.; Ferrie, A.; Juurlink, B.H.J. Dietary approach to attenuate oxidative stress, hypertension, and inflammation in the cardiovascular system. Proc. Natl. Acad. Sci. USA 2021, 118, e2021450118. [Google Scholar] [CrossRef]
  8. Kelemen, L.E.; Cerhan, J.R.; Lim, U.; Davis, S.; Cozen, W.; Schenk, M.; Colt, J.; Hartge, P.; Ward, M.H. Vegetables, fruit, and antioxidant-related nutrients and risk of non-Hodgkin lymphoma: A National Cancer Institute–Surveillance, Epidemiology, and End Results population-based case-control study. Am. J. Clin. Nutr. 2006, 83, 1401–1410. [Google Scholar] [CrossRef]
  9. Liu, R.H. Health-Promoting Components of Fruits and Vegetables in the Diet. Adv. Nutr. 2013, 4, 384S–392S. [Google Scholar] [CrossRef]
  10. Chen, T.; Wang, Q.; Wang, Y.; Dou, Z.; Yu, X.; Feng, H.; Wang, M.; Zhang, Y.; Yin, J. Using fresh vegetable waste from Chinese traditional wet markets as animal feed: Material feasibility and utilization potential. Sci. Total Environ. 2023, 902, 166105. [Google Scholar] [CrossRef]
  11. Chatterjee, S.; Mohan, S.V. Pretreatment of fruit and vegetable waste for the production of biofuels and high-value products. In Fruit and Vegetable Waste Utilization and Sustainability; Mandavgane, S.A., Chakravarty, I., Jaiswal, A.K., Eds.; Academic Press: London, UK, 2023; pp. 285–299. [Google Scholar]
  12. Dufour, M.; Chaunier, L.; Lourdin, D.; Réguerre, A.L.; Hugon, F.; Dugué, A.; Kansou, K.; Saulnier, L.; Della Valle, G. Unravelling the relationships between wheat dough extensional properties, gluten network and water distribution. Food Hydrocoll. 2024, 146, 109214. [Google Scholar] [CrossRef]
  13. Magro, P.C.; Maestro-Gaitán, I.; Blázquez, M.R.; Prieto, J.M.; Iñiguez, F.M.S.; Sobrado, V.C.; Gómez, M.J.R. Determination of nutritional signatures of vegetable snacks formulated with quinoa, amaranth, or wheat flour. Food Chem. 2024, 433, 137370. [Google Scholar] [CrossRef] [PubMed]
  14. MAPA. Métodos Oficiales de Análisis en la Unión Europea. Ministerio de Agricultura, Pesca y Alimentación; Secretaría General Técnica: Madrid, Spain, 1998; p. 495. [Google Scholar]
  15. FAO. Food Analysis: General Techniques, Additives, Contaminants, and Composition. In Manuals of Food Quality Control 7; Food and Agriculture Organization of the United Nations: Rome, Italy, 1993; pp. 105–109. [Google Scholar]
  16. ANKOM. Crude fiber analysis in feeds by filter bag technique. In ANKOM Technology Method 7, AOCS Approved Procedure Ba6a-05; ANKOM Technology: Macedon, NY, USA, 2008; p. 3. [Google Scholar]
  17. Sullivan, D.M. Proximate and Mineral Analysis. In Analysis of Nutrition Labeling; Sullivan, D.M., Carpenter, D.E., Eds.; AOAC International: Arlington, VA, USA, 1993; pp. 105–109. [Google Scholar]
  18. Martínez, E.; Pardo, J.E.; Rabadán, A.; Álvarez-Ortí, M. Effects of Animal Fat Replacement by Emulsified Melon and Pumpkin Seed Oils in Deer Burgers. Foods 2023, 12, 1279. [Google Scholar] [CrossRef] [PubMed]
  19. Boff, J.M.; Strasburg, V.J.; Ferrari, G.T.; de Oliveira Schmidt, H.; Manfroi, V.; de Oliveira, V.R. Chemical, Technological, and Sensory Quality of Pasta and Bakery Products Made with the Addition of Grape Pomace Flour. Foods 2022, 11, 3812. [Google Scholar] [CrossRef] [PubMed]
  20. Lozano, R.D. Color and Visual Appearance in Foods. In Color in Food. Technological and Psychophysical Aspects; Caivano, J.L., Buera, M.P., Eds.; CRC Press: Boca Raton, FL, USA, 2012. [Google Scholar]
  21. Sharma, S.; Katoch, V.; Kumar, S.; Chatterjee, S. Functional relationship of vegetable colors and bioactive compounds: Implications in human health. J. Nutr. Biochem. 2021, 92, 108615. [Google Scholar] [CrossRef] [PubMed]
  22. Martins, T.; Barros, A.N.; Rosa, E.; Antunes, L. Enhancing Health Benefits through Chlorophylls and Chlorophyll-Rich Agro-Food: A Comprehensive Review. Molecules 2023, 28, 5344. [Google Scholar] [CrossRef]
  23. Mironeasa, S.; Iuga, M.; Zaharia, D.; Mironeasa, C. Rheological Analysis of Wheat Flour Dough as Influenced by Grape Peels of Different Particle Sizes and Addition Levels. Food Bioprocess. Technol. 2019, 12, 228–245. [Google Scholar] [CrossRef]
  24. Komeroski, M.R.; de Oliveira, V.R. Influence of the Amount and Type of Whey Protein on the Chemical, Technological, and Sensory Quality of Pasta and Bakery Products. Foods 2023, 12, 2801. [Google Scholar] [CrossRef]
  25. Biesiekierski, J.R. What is gluten? J. Gastroenterol. Hepatol. 2017, 32 (Suppl. S1), 78–81. [Google Scholar] [CrossRef]
  26. Jiang, G.; Feng, X.; Wu, Z.; Li, S.; Bai, X.; Zhao, C.; Ameer, K. Development of wheat bread added with insoluble dietary fiber from ginseng residue and effects on physiochemical properties, in vitro adsorption capacities and starch digestibility. LWT 2021, 149, 111855. [Google Scholar] [CrossRef]
  27. Tolve, R.; Simonato, B.; Rainero, G.; Bianchi, F.; Rizzi, C.; Cervini, M.; Giuberti, G. Wheat Bread Fortification by Grape Pomace Powder: Nutritional, Technological, Antioxidant, and Sensory Properties. Foods 2021, 10, 75. [Google Scholar] [CrossRef]
  28. Ozón, B.; Cotabarren, J.; Geier, F.R.; Kise, M.P.; García-Prado, J.; Parisi, M.G.; Obregón, W.D. Development of Fortified Breads Enriched with Plant-Based Bioactive Peptides Derived from the Chia (Salvia hispanica L.) Expeller. Foods 2023, 12, 3382. [Google Scholar] [CrossRef] [PubMed]
  29. Ribeiro, T.C.; Abreu, J.P.; Freitas, M.C.J.; Pumar, M.; Teodoro, A.J. Substitution of wheat flour with cauliflower flour in bakery products: Effects on chemical, physical, antioxidant properties and sensory analyses. Int. Food Res. J. 2015, 22, 532–538. [Google Scholar]
  30. Murcia, M.A.; López-Ayerra, B.; García-Carmona, F. Effect of Processing Methods and different Blanching Times on Broccoli: Proximate Composition and Fatty Acids. LWT 1999, 32, 238–243. [Google Scholar] [CrossRef]
  31. Millar, K.A.; Gallagher, E.; Burke, R.; McCarthy, S.; Barry-Ryan, C. Proximate composition and anti-nutritional factors of fava-bean (Vicia faba), green-pea and yellow-pea (Pisum sativum) flour. J. Food Compos. Anal. 2019, 82, 103233. [Google Scholar] [CrossRef]
  32. Nichols, R.G.; Davenport, E.R. The relationship between the gut microbiome and host gene expression: A review. Hum. Genet. 2021, 140, 747–760. [Google Scholar] [CrossRef]
  33. Campas-Baypoli, O.N.; Sánchez-Machado, D.I.; Bueno-Solano, C.; Núñez-Gastélum, J.A.; Reyes-Moreno, C.; López-Cervantes, J. Biochemical composition and physicochemical Properties of broccoli flours. Int. J. Food Sci. Nutr. 2009, 60, 163–173. [Google Scholar] [CrossRef]
  34. Baloch, A.B.; Xia, X.; Sheikh, S.A. Proximate and Mineral Compositions of Dried Cauliflower (Brassica oleracea L.) Grown in Sindh, Pakistan. J. Food Nutr. Res. 2015, 3, 213–219. [Google Scholar] [CrossRef]
  35. Llorach, R.; Espín, J.C.; Tomás-Barberán, F.A.; Ferreres, F. Valorization of Cauliflower (Brassica oleracea L. Var. botrytis) By-Products as a Source of Antioxidant Phenolics. J. Agric. Food. Chem. 2003, 51, 2181–2187. [Google Scholar] [CrossRef]
  36. Kumar, S.; Andy, A. MiniReview. Health promoting bioactive phytochemicals from Brassica. Int. Food Res. J. 2012, 19, 141–152. [Google Scholar]
  37. Podsędek, A. Natural antioxidants and antioxidant capacity of Brassica vegetables: A review. LWT 2007, 40, 1–11. [Google Scholar] [CrossRef]
  38. Esteve, M. Mechanisms Underlying Biological Effects of Cruciferous Glucosinolate-Derived Isothiocyanates/Indoles: A Focus on Metabolic Syndrome. Front. Nutr. 2020, 7, 111. [Google Scholar] [CrossRef] [PubMed]
  39. Langston, F.; Redha, A.A.; Nash, G.R.; Bows, J.R.; Torquati, L.; Gidley, M.J.; Cozzolino, D. Qualitative analysis of broccoli (Brassica oleracea var. italica) glucosinolates: Investigating the use of mid-infrared spectroscopy combined with chemometrics. J. Food Compos. Anal. 2023, 123, 105532. [Google Scholar] [CrossRef]
  40. Guiné, R.P.F. Textural Properties of Bakery Products: A Review of Instrumental and Sensory Evaluation Studies. Appl. Sci. 2022, 12, 8628. [Google Scholar] [CrossRef]
  41. De Kock, H.K.; Magano, N.N. Sensory tools for the development of gluten-free bakery foods. J. Cereal Sci. 2020, 94, 102990. [Google Scholar] [CrossRef]
  42. Stantiall, S.E.; Serventi, L. Nutritional and sensory challenges of gluten-free bakery products: A review. Int. J. Food Sci. Nutr. 2017, 69, 427–436. [Google Scholar] [CrossRef]
Agriculture 14 01747 g001
Figure 1. External appearance of the flour, the dough, and the baked products made with pea, broccoli, and cauliflower waste.
Figure 1. External appearance of the flour, the dough, and the baked products made with pea, broccoli, and cauliflower waste.
Agriculture 14 01747 g001
Agriculture 14 01747 g002
Figure 2. The evolution of color during processing, from the raw material before dehydration until the baked product. In the control sample, there was no measure for the raw material since the commercial flour was acquired in local markets directly for use. The red lines represent the red-green component (a*), while the blue lines represent the yellow-blue component (b*).
Figure 2. The evolution of color during processing, from the raw material before dehydration until the baked product. In the control sample, there was no measure for the raw material since the commercial flour was acquired in local markets directly for use. The red lines represent the red-green component (a*), while the blue lines represent the yellow-blue component (b*).
Agriculture 14 01747 g002
Agriculture 14 01747 g003
Figure 3. The content of the total phenolic compounds in the flours (green bar) and baked products (orange bar). In both the wheat flour and the baked product obtained from it, no phenolics were detected. n.d.: not detected.
Figure 3. The content of the total phenolic compounds in the flours (green bar) and baked products (orange bar). In both the wheat flour and the baked product obtained from it, no phenolics were detected. n.d.: not detected.
Agriculture 14 01747 g003
Agriculture 14 01747 g004
Figure 4. Antioxidant capacity, measured as a DPPH inhibition percentage, of the wheat, pea, broccoli, and cauliflower flours, and the baked products made from them. Different letters indicate significant differences in flours or baked products (p < 0.05).
Figure 4. Antioxidant capacity, measured as a DPPH inhibition percentage, of the wheat, pea, broccoli, and cauliflower flours, and the baked products made from them. Different letters indicate significant differences in flours or baked products (p < 0.05).
Agriculture 14 01747 g004
Agriculture 14 01747 g005
Figure 5. The average values from the sensory analysis regarding external appearance, smell, texture, and taste.
Figure 5. The average values from the sensory analysis regarding external appearance, smell, texture, and taste.
Agriculture 14 01747 g005
Table 1. Ingredients used for the production of the doughs.
Table 1. Ingredients used for the production of the doughs.
ProductFlourSaltWater
ControlWheat 200 g5 g120 mL
BroccoliWheat 100 g
Broccoli 100 g		5 g225 mL
CauliflowerWheat 100 g
Cauliflower 100 g		5 g225 mL
PeaWheat: 100 g
Pea: 100 g		5 g170 mL
Table 2. Texture parameters of the doughs made with flours obtained from frozen vegetable waste.
Table 2. Texture parameters of the doughs made with flours obtained from frozen vegetable waste.
Control (Wheat)BroccoliCauliflowerPea
Hardness (N)50.95 c ± 4.89298.46 a ± 18.5785.48 bc ± 9.68119.42 b ± 0.13
Cohesiveness0.271 a ± 0.0130.212 b± 0.0040.204 b ± 0.0350.158 c ± 0.002
Springiness0.257 b ± 0.0460.401 a ± 0.0360.162 c ± 0.0350.261 b ± 0.018
Adhesiveness (N·s)−0.788 c ± 1.031−2.487 b ± 0.701−7.161 a ± 2.905−1.338 bc ± 0.079
Different letters in the same line indicate significant differences (p < 0.05).
Table 3. Approximate composition of the baked products made with doughs supplemented with 50% of the vegetable flours.
Table 3. Approximate composition of the baked products made with doughs supplemented with 50% of the vegetable flours.
Control (Wheat)BroccoliCauliflowerPea
Protein (%)9.63 c ± 0.6720.88 a ± 1.4616.19 b ± 1.2915.94 b ± 1.27
Ash (%)3.67 c ± 0.115.93 ab ± 0.476.48 a ± 0.194.86 bc ± 0.19
Crude fiber (%)0.67 c ± 0.048.13 a ± 0.498.58 a ± 0.266.00 b ± 0.03
Crude Fat (%)0.06 c ± 0.001.69 a ± 0.041.06 b ± 0.041.19 b ± 0.04
Total Carbohydrates (%)86.65 a ± 6.0671.51 b ± 5.0076.27 b ± 5.4678.01 b ± 5.46
Available Carbohydrates (%)85.98 a ± 4.2363.38 c ± 1.9067.69 bc ± 4.3272.01 b ± 4.32
Energy value (kcal/100 g dm)386385379379
Different letters in the same line indicate significant differences (p < 0.05).
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Gallardo, M.A.; Martínez-Navarro, M.E.; Álvarez-Ortí, M.; Pardo, J.E. Utilization of Flours Derived from the Waste from the Frozen Vegetable Industry for Bakery Product Production. Agriculture 2024, 14, 1747. https://doi.org/10.3390/agriculture14101747

AMA Style

Gallardo MA, Martínez-Navarro ME, Álvarez-Ortí M, Pardo JE. Utilization of Flours Derived from the Waste from the Frozen Vegetable Industry for Bakery Product Production. Agriculture. 2024; 14(10):1747. https://doi.org/10.3390/agriculture14101747

Chicago/Turabian Style

Gallardo, Miguel A., María Esther Martínez-Navarro, Manuel Álvarez-Ortí, and José E. Pardo. 2024. "Utilization of Flours Derived from the Waste from the Frozen Vegetable Industry for Bakery Product Production" Agriculture 14, no. 10: 1747. https://doi.org/10.3390/agriculture14101747

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop