Valorization of Peach Fruit and Wine Lees through the Production of a Functional Peach and Grape Juice

The valorization of agri-food products not only represents important economic and environmental benefits but can also be a source of potentially profitable, functional, and safe ingredients. This study aimed to valorize peach fruit and wine lees (WL) by producing functional juice. WL were incorporated at different concentrations (1.5 and 2%; w:w) in unpasteurized peach and grape juice and subsequently stored under refrigeration (5 °C). The antimicrobial activity of WL in peach and grape juices was assessed against Listeria monocytogenes and Saccharomyces cerevisiae as well as physicochemical, nutritional microbiological, and sensory acceptability. The maximum addition of WL to the juice (2%) showed a significant inhibitory effect against L. monocytogenes (4-log reduction) and increased the content of total soluble solids (TSS) (10%), total polyphenol content (TPC) (75%), and total antioxidant activity (AOX) (86%). During storage, AOX, TPC, TSS, pH, and titratable acidity (TA) remained stable. A significant correlation was observed between TPC and AOX. Total mesophilic aerobic bacteria and yeast counts increased during storage. Fifty-seven percent of tasters (n = 26) rated the functional juice positively. Thus, these agri-food products could be useful for producing functional juices with a longer shelf life, contributing to their valorization.

Selection of a Probiotic for Its Potential for Developing a Synbiotic Peach and Grape Juice

Due to recent interest in the potential of probiotics as health promoters and the impact of health and environmental concerns on eating habits, non-dairy probiotic food products are required. This study aimed to evaluate the viability of different probiotic microorganisms in peach and grape juice (PGJ) with or without the prebiotic inulin and their antimicrobial activity against the foodborne pathogen Listeria monocytogenes and the juice spoilage microorganism Saccharomyces cerevisiae. Firstly, the viability of seven probiotic strains was studied in PGJ with an initial concentration of 107 CFU/mL for 21 days at 4 °C and for 3 days at 37 °C. In parallel, the physicochemical effect, the antimicrobial effect and the lactic acid production in PGJ were evaluated. Secondly, the probiotic with the best viability results was selected to study its antimicrobial effect against L. monocytogenes and S. cerevisiae, as well as ethanol and acetaldehyde production by the latter. L. casei showed the highest viability and grew in both refrigerated and fermentation conditions (1 log), produced the greatest lactic acid (5.12 g/L) and demonstrated in vitro anti-Listeria activity. Although the addition of the prebiotic did not improve the viability, lactic acid production or anti-Listeria activity of the probiotics, under the conditions studied, the prebiotic potential of inulin, support the design of a synbiotic juice. Finally, although none of the probiotic, fermentation products, or postbiotics showed any antimicrobial activity against L. monocytogenes or S. cerevisiae, the addition of L. casei to the PGJ significantly reduced the production of S. cerevisiae metabolite ethanol (29%) and acetaldehyde (50%). L. casei might be a suitable probiotic to deliver a safe and functional PGJ, although further research should be carried out to determine the effect of the probiotic and fermentation on the nutritional profile of PGJ.

Exploring the Nutritional Potential of Microalgae in the Formulation of Bakery Products

Microalgae have positioned themselves as an innovative and sustainable source of bioactive compounds and high nutritional value. The selection of a suitable food carrier is important to ease its consumption, and to preserve bioactivity through food processing. The aim of this study was to assess the suitability of different microalgae in baked products. Crackers and grissini were produced following a specific formulation, with percentages ranging from 1.5 to 3.5% of flour substituted with Spirulina, Chlorella, and Tetraselmis dry biomass in the formulas. Physico-chemical, nutritional, and sensorial characterization was carried out. The incorporation of microalgae led to increased nutritional values, including antioxidant capacity (AOX), total phenolic content (TPC) and protein content with an amino acids' identification and quantification. Grissini with Chlorella at 3.5% and crackers with Spirulina at 1.5% levels, showed a higher overall acceptance within the panelists. For amino acid content, Spirulina crackers were shown to be rich in alanine, aspartate, and tryptophan, while Chlorella grissini stood out for being particularly rich in isoleucine, leucine, lysine, and valine. Thus, Spirulina and Chlorella could be a sustainable ingredient to formulate baked goods with an enhanced nutrimental matrix without altering their acceptability to consumers.

Effect of Spirulina in Bread Formulated with Wheat Flours of Different Alveograph Strength

Consumers within the EU are increasingly asking for natural and healthier food products, which are additive-free and environmentally friendly. The aim of this study was to assess the effects of Spirulina (Arthrospira sp.) in bread formulated with four wheat flours with different alveograph strengths. The flours used were Manitoba Flour (00/251), Ground-force wholemeal (Whole/126), Standard Bakery Flour (0/W105), and Organic Bakery Flour (2/W66). Powdered Spirulina biomass was used as a new ingredient with a high nutritional profile and bioactive compounds; incorporation was made at two levels: 1.5% and 2.5% of the flour amount. The same bread recipe was used for all formulations, but for the 1.5 and 2.5% variations, 6 g and 10 g of Spirulina were added, respectively. Antioxidant capacity increased with increasing microalgal biomass. The visual and taste attributes of the breads with microalgae underwent noticeable changes compared to their counterparts without microalgae. Biomass addition significantly (p < 0.05) affected bread weight and volume, and different trends were found based on the type of wheat flour. Spirulina-containing breads showed a greener coloration while the microalgae concentration was augmented. The moisture and texture were slightly affected by the addition of the biomass at both levels. The 2.5% concentration samples were well accepted in most cases by consumers, emphasizing the salty flavor as a pleasant feature. No significant sensory differences were observed between samples, and the acceptability index was always higher than 72%. The results show that Spirulina could be an environmentally friendly ingredient for the reformulation of nutritionally enhanced bread with a good texture that is well-accepted by consumers.

Multiple reaction monitoring for identification and quantification of oligosaccharides in legumes using a triple quadrupole mass spectrometer

Raffinose family oligosaccharides are non-digestible compounds considered as dietary prebiotics with health-related properties. Hence, it is important to develop highly specific methods for their determination. An analytical method is developed in this study for oligosaccharide identification and quantification using liquid chromatography-tandem mass spectrometry equipped with a triple quadrupole analyser operating in Multiple Reaction Monitoring mode. Raffinose, stachyose and verbascose are separated in a 10-minute run and the method is validated over a broad concentration range, showing good linearity, accuracy, precision and high sensitivity. A low-cost, short eco-friendly procedure for oligosaccharide extraction from legumes, with a high recovery rate extraction, good repeatability and reproducibility is also proposed. No plant-matrix effects were demonstrated. The method applied to the screening of 28 different legumes revealed species-related traits for oligosaccharide distribution, highlighting Pisum sativum (9.22 g/100 g) as the richest source of these prebiotics and its suitability as a functional food ingredient.

Relationship between color and betalain content in different thermally treated beetroot products

Several health benefits are currently attributed to natural pigments that give fruit and vegetables their inherently colorful properties. Color measurements might therefore serve as quick indicators of the potential health-promoting properties of such foods. Nevertheless, the relationship between color and pigment content depends on the type of matrix and pigment, as well as the factors affecting their interaction, which calls for further investigation. Hence, the aim of the present study is to investigate the relationship between color parameters and betalain content in three commonly consumed beetroot products (beetroot juice, beetroot puree and whole beetroot), subjected to thermal treatment. Our results showed a negative correlation between the total betalain content and the color parameters L*, a*, b*, chroma, and hue angle in beetroot juice, beetroot puree and whole beetroot. Two chromatic parameters, a* and chroma, are proposed as the best descriptors for the betalain concentrations of these products. Likewise, the tristimulus L/ab combination for the juice is also suggested as a good descriptor. Our findings highlighted that the relationship between color and total betalain content depended on the beetroot product under assessment, with the strongest correlations found for the juice. Squeezed beetroot was therefore suggested as an alternative to improve this relationship in more complex matrices such as whole cooked beetroots. Useful information from color determination sheds light on the relationship between color and betalain pigments in beetroot, suggesting that color determination could be used as an indicator of betalain content.