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 β-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.

Tannase is an inducible enzyme which hydrolysate tannin to gallic acid and used to in many industries such as food and pharmaceutical. This enzyme has scooped more attention in recent times. A maximum production of tannase (ranged from 0.30 to 0.93 enzyme index and from1.05 to 1.87 U/mg specific tannase activity (STA)) and gallic acid (from 0.07 to 0.76 mg/ml gallic acid concentration (GAC)) was achieved by 8 fungal strains out of 24 fungal and yeast strains belonged to genera; Aspergillus, Rhizopus, Trichoderma, Fusarium, Penicillium, Candida and Saccharomyces. The selected fungi were grown on tannin-rich substrates (eucalyptus leaves, pomegranate peel, banana peel, guava leaves and wheat bran) and by-products (corn steep liquor (CSL) and soybean extract) as sole carbon and nitrogen sources for tannase and GA production at 28°C for 6 days under liquid-surface (LSF), submerged (SmF) and solid-state (SSF) fermentation. Results indicated that A. niger A8 and T. viride with 10% (v/v) of inoculum size gave a high STA (from 8.08 to 10.95 U/mg) and GAC (from 2.62 to 4.00 mg/ml) on pomegranate and banana peels supplemented with CSL after 4 days incubation at 28°C under SSF compared to SmF and LSF. STA (ranged from 10.68 to 12.93 U/mg) and GAC (ranged from 3.56 to 4.16 mg/ml) were increased when inoculated the medium with both A. niger A8+T. viride (with 5:5% v/v of inoculum size) more than when inoculated with each of them separately.

Decolorization of textile reactive azo dyes blue and yellow by 15 isolates have obtained from arid soil were we compared. Isolate S8 showing the highest decolorization performance was has selected and completely identified through molecular approach based on sequencing of the cpn60 universal target (UT) as Klebsiella oxytoca. The effect of various external parameters on improving decolorization of dyes abilities of this strain was has studied. Maximum decolorization of dyes activity occurred at a medium containing glucose, soybean husk at C/N ratio of 12:1 supplemented with dye concentration of 100 mg per L and amended with 3 percentage (v to v) inoculum. Incubation at 35°C ±2 with shaking at 150 rpm for 4 days reaching 89.35 and 78.23 precentage for blue and yellow dyes respectively. The high induction of enzymes azo-reductase, phenol red manganese peroxidase enzyme and ascorbate oxidase enzyme indicated that their prominent role in dye has been degradation.