The Preservative Action of Protein Hydrolysates from Legume Seed Waste on Fresh Meat Steak at 4 °C: Limiting Unwanted Microbial and Chemical Fluctuations.

Valorizing agricultural wastes to preserve food or to produce functional food is a general trend regarding the global food shortage. Therefore, natural preservatives were developed from the seed waste of the cluster bean and the common bean to extend the shelf life of fresh buffalo meat steak and boost its quality via immersion in high-solubility peptides, cluster bean protein hydrolysate (CBH), and kidney bean protein hydrolysate (RCH). The CBH and the RCH were successfully obtained after 60 min of pepsin hydrolysis with a hydrolysis degree of 27−30%. The SDS-PAGE electropherogram showed that at 60 min of pepsin hydrolysis, the CBH bands disappeared, and RCH (11−48 kD bands) nearly disappeared, assuring the high solubility of the obtained hydrolysates. The CBH and the RCH have considerable antioxidant activity compared to ascorbic acid, antimicrobial activity against tested microorganisms compared to antibiotics, and significant functional properties. The CBH and the RCH (500 µg/mL) successfully scavenged 93 or 89% of DPPH radicals. During the 30-day cold storage (4 °C), the quality of treated and untreated fresh meat steaks was monitored. Protein hydrolysates (500 g/g) inhibited lipid oxidation by 130−153% compared to the control and nisin and eliminated 31−55% of the bacterial load. The CBH and the RCH (500 µg/g) significantly enhanced meat redness (a* values). The protein maintained 80−90% of the steak's flavor and color (p < 0.05). In addition, it increased the juiciness of the steak. CBH and RCH are ways to valorize wastes that can be safely incorporated into novel foods.

Biochemical and Functional Characterization of Kidney Bean Protein Alcalase-Hydrolysates and Their Preservative Action on Stored Chicken Meat.

A new preservation approach is presented in this article to prolong the lifetime of raw chicken meat and enhance its quality at 4 °C via coating with highly soluble kidney bean protein hydrolysate. The hydrolysates of the black, red, and white kidney protein (BKH, RKH, and WKH) were obtained after 30 min enzymatic hydrolysis with Alcalase (E/S ratio of 1:100, hydrolysis degree 25-29%). The different phaseolin subunits (8S) appeared in SDS-PAGE in 35-45 kD molecular weight range while vicilin appeared in the molecular weight range of 55-75 kD. The kidney bean protein hydrolysates have considerable antioxidant activity as evidenced by the DPPH-scavenging activity and ß-carotine-linolenic assay, as well as antimicrobial activity evaluated by disc diffusion assay. BKH followed by RKH (800 µg/mL) significantly (p ≤ 0.05) scavenged 95, 91% of DPPH and inhibited 82-88% of linoleic oxidation. The three studied hydrolysates significantly inhibited the growth of bacteria, yeast, and fungi, where BKH was the most performing. Kidney bean protein hydrolysates could shield the chicken meat because of their amphoteric nature and many functional properties (water and oil-absorbing capacity and foaming stability). The quality of chicken meat was assessed by tracing the fluctuations in the chemical parameters (pH, met-myoglobin, lipid oxidation, and TVBN), bacterial load (total bacterial count, and psychrophilic count), color parameters and sensorial traits during cold preservation (4 °C). The hydrolysates (800 µg/g) significantly p ≤ 0.05 reduced the increment in meat pH and TVBN values, inhibited 59-70% of lipid oxidation as compared to control during 30 days of cold storage via eliminating 50% of bacterial load and maintained secured storage for 30 days. RKH and WKH significantly (p ≤ 0.05) enhanced L*, a* values, thus augmented the meat whiteness and redness, while, BKH increased b* values, declining all color parameters during meat storage. RKH and WKH (800 µg/g) (p ≤ 0.05) maintained 50-71% and 69-75% of meat color and odor, respectively, increased the meat juiciness after 30 days of cold storage. BKH, RKH and WKH can be safely incorporated into novel foods.

Optimizing the Addition of Functional Plant Extracts and Baking Conditions To Develop Acrylamide-Free Pita Bread.

The effects of using freeze-dried extracts (FDEs) of spearmint ( Mentha spicata), fennel ( Foeniculum vulgare), and turmeric ( Curcuma longa) as well as adjusting the baking temperature and time on acrylamide formation in pita bread were investigated to obtain the most acceptable conditions that produced the lowest acrylamide concentrations. A Box-Behnken design was adopted for optimization of the pita bread formulations by adding FDEs (3 to 25 g/100 g of wheat flour) and adjusting the baking temperature (200 to 300°C) and baking time (3 to 11 min), and the effects of these changes on color parameters, phytochemical attributes, and acrylamide concentrations were evaluated. Increasing the concentration of FDE and decreasing the baking temperature and time considerably decreased the acrylamide concentration in bread for all experimental trials. No acrylamide was detected in pita bread formulated with 25 g of mint FDE/100 g of wheat flour and baked at 250°C for 3 min, formulated with 25 g of mint or fennel FDE/100 g and baked at 300°C for 7 min, formulated with 3 g of mint, fennel, or turmeric FDE/100 g and baked at 200°C for 7 min, formulated with 14 g of mint FDE/100 g and baked at 300°C for 3 min, and formulated with 25 g of mint or fennel FDE/100 g and baked at 200°C for 7 min. Pita breads formulated with fennel and turmeric FDE were given high sensory scores.