The main objective of the present study was to evaluate the influence of encapsulation by extrusion technique using two hydrogels, namely; sodium alginate (Na-ALG) and whey protein isolate (WPI) on Bifidobacterium bifidium viability and stability of yoghurt under simulated gastrointestinal conditions. Probiotic bacteria (free or encapsulated) were added to yogurt for four weeks to test their viability and stability. Physicochemical and sensory analysis of yoghurt were conducted. Viability of B. bifidium in the simulated gastrointestinal conditions pH 2 and pH 7.5 was determined. Also, the efficiency of encapsulated final yield of the microcapsules was determined. With storage time, the pH of yoghurt containing encapsulated bacteria increased more than that of yoghurt containing free probiotic bacteria, resulting in a decrease in acidity. When compared to yoghurt containing encapsulated bacteria, the lactose level of yoghurt containing free probiotic bacteria decreased over time. The viscosity of yoghurt containing encapsulated WPI remained stable over the storage period, with syneresis remaining stable. The sensory properties of yoghurt containing free probiotics deteriorated over time. Cell viability was significantly reduced in yoghurt-containing free probiotics compared to other treated yoghurts. Cell viability in free probiotics yoghurt was lower than in encapsulated ones when exposed to simulated gastric and intestinal juice. In conclusion, WPI- encapsulated probiotics showed better stability over 28 days of storage in both yoghurt and gastrointestinal conditions, followed by sodium alginate.

The aim was to develop nutritious drinks using date nectar with the two most popular Saudi date cultivars (Khalas and Sukkari) and spirulina at different substitution rates. The date puree was prepared with different concentrations of pectin enzymes. The approximate composition, microbiological quality, sugars, vitamins, and minerals of date puree and spirulina, as well as the contaminants, physical properties, fatty acids, and phytopigments of spirulina were evaluated. Chemical composition and sensory properties of the developed date drinks were also assessed. The results showed that spirulina is safe, free from contaminants and heavy metals, and appeared to contain appreciable amounts of essential fatty acids, amino acids, vitamins, minerals, and phytopigments. The microbiological loads of date puree and spirulina were very low, and there were no pathogenic microbes were found. Spirulina contained higher amounts of total solids, ash, protein, minerals, fiber, fat, and vitamins, than date puree, indicating its suitability as a rich source of nutrients for food fortification. In both date types, treatment of puree with 400 ppm enzyme yielded nectar with higher scores in all sensory attributes, indicating that this is a suitable concentration to yield acceptable juice amounts. The substitution of date nectar with 10% spirulina gave the highest scores for sensory attributes; consequently, this concentration was used for the formulation of functional nectar from date nectar and spirulina. Incorporation of 10% spirulina in date nectars showed a significant increase in the contents of total solids, protein, essential amino acids, ash, fat, sugars, carotenoids, and chlorophyll in the date nectars, thereby improving its nutritional and health properties.

The large family of enzymes, known as polyphenols oxidases, includes laccase. Due to the inclusion of a copper atom in their catalytic core, laccases are frequently referred to as multi-copper oxidases. Laccases are versatile enzymes that can catalyze the oxidation of a wide range of phenolic and non-phenolic substances. In the current study, a local strain of Aspergillus niger was used for solid-state fermentation to produce fungal laccase, as well as purify and optimize laccase. The enzyme profile, which was acquired using guaiacol to measure enzyme activity, showed that after five days of incubation, wheat straw provided the highest level of laccase activity, or 2.551 U/mL. A technique called response surface methodology (RSM) was used to examine the effects of various conditions on the production of enzymes. The RSM results demonstrated that after five days of incubation, the enzyme activity was at its highest at 45 °C, pH 5.5, and 30% moisture level, inoculated with 2 mL mycelium. Through ammonium sulphate precipitation and dialysis, the enzyme was purified. Additionally, column chromatography was used to further purify laccase. The next step was enzyme characterization to evaluate how temperature and pH affected enzyme activity. At 45 °C and pH 5.5, the isolated enzyme produced its highest level of activity. The findings of the current study showed that A. niger is capable of producing laccase in an economical and environmentally friendly way. Due to its unique oxidative and catalytic features, this enzyme has received a lot of attention recently.

The pectinase enzymes are involved in several industrial applications, and industrial waste is one of the largest environmental pollutants, so this study aims to Endo-polygalacturonase (endo-PG) producing using Aspergillus niger AUMC 4156, Penicillium oxalicum AUMC 4153 and P. variotii AUMC 4149 by using some agro-industrial wastes (dried orange peel and sugar beet pulp) as a sole raw carbon source for degradation these waste in the process of urban wastes disposal. The fermentation process was carried out as a submerged culture technique under both shaken and static culture conditions. A. niger AUMC 4156 was the most promising producer of endo-PG under static conditions while P. oxalicum AUMC 4153 was the highest producer of endo-PG under shaken conditions. Sugar beet pulp proved to be the most preferable to orange peel as the only source of carbon in both shaken and static cultures. The medium that encompassing orange peel as a single carbon source afforded the highest protein content with all tested fungal strains in stirred and static cultures in comparison with sugar beet pulp. The highest activity of endo-polygalacuronase that produced using A. niger AUMC 4156 and P. oxalicum AUMC 4153 was achieved by using sugar beet pulp at 3% concentration under static cultures, meanwhile maximal enzyme activity produced by both fungal strains required 2% sugar beet pulp under shaken cultures. Sugar beet pulp showed promised potential as a good inducer for endo-polygalacturoase production, and enzymes production depended on fungal strains, culture medium, and submerged fermentation conditions.

This study aimed to investigate the effect of different concentrations (0, 0.5, 1, 1.5, and 2%) of clove powder on the physicochemical, nutritional, and sensorial quality and storage stability of cookies. The results showed significantly (P ≤ .05) increases in the peak viscosity, breakdown, final viscosity, setback, hardness, cohesiveness, springiness, adhesiveness, chewiness, water holding capacity, and oil holding capacity, and reduction of pasting temperature of cookie flour containing clove powder compared to control. In cookies, the incorporation of clove powder significantly (p ≤ .05) increased diameter, thickness, hardness, factorability, redness (a*), and moisture. The significant increasing significantly (p ≤ .05) in cookies content was: macronutrients (Protein (10.65 ± 0.03 to 10.62 ± 0.07), Fat (14.52 ± 0.15 to 15.48 ± 0.07), Ash (1.08 ± 0.05 to 1.35 ± 0.00)%), minerals (K (12.04 ± 0.78 to 35.16 ± 0.76), Mg (12.62 ± 0.45 to 17.63 ± 0.04), Fe (8.14 ± 0.06 to 8.61 ± 0.02), P (10.51 ± 0.94 to 13.52 ± 0.12), Zn (0.31 ± 0.01 to 0.53 ± 0.00), Ca (56.89 ± 0.31 to 66.97 ± 0.43) (mg/kg)), also, TPC (12.93 ± 1.8 to 34.07 ± 1.9 (mg GAE/g)), and DPPH (% inhibition) was increased from (15.73 ± 1.4 to 28.51 ± 1.7) in control and 2% clove cookies respectively. However, it reduced the spread ratio, water activity, lightness (L*), and yellowness (b*) of cookies (p ≤ .05). Clove powder also improves the storage stability of cookies. Overall, incorporating clove powder into cookies enhanced the physicochemical, nutritional, bioactive properties, and storability without a major effect on the sensory acceptability of the developed product.