Functionalized electrospun nanofibers to enhance ß-Galactosidase immobilization and catalytic activity for efficient galactooligosaccharide synthesis.

This study aimed to immobilize ß-galactosidase (ß-GAL) into enhanced polystyrene (PS) electrospun nanofiber membranes (ENMs) with functionalized graphene oxide (GO). Initially, GO sheets were functionalized by salinization with 3-aminopropyl triethoxysilane (APTES). Then the ENMs (PS, PS/GO, and PS/GO-APTES) were prepared and characterized. Then, the ß-GAL was immobilized in the different ENMs to produce the ß-GAL-bound nanocomposites (PS-GAL, PS/GO-GAL, and PS/GO-APTES-GAL). Immobilization of ß-GAL into PS/GO-APTES significantly improved enzyme adsorption by up to 87 %. Also, PS/GO-APTES-GAL improved the enzyme activity, where the highest enzyme activity was obtained at enzyme concentrations of 4 mg/L, 50 °C, and pH 4.5. Likewise, the storage stability and reusability of immobilized ß-GAL were improved. Furthermore, this process led to enhanced catalytic behavior and transgalactosylation efficiency, where GOS synthesis (72 %) and lactose conversion (81 %) increased significantly compared to the free enzyme. Overall, the immobilized ß-GAL produced in this study showed potential as an effective biocatalyst in the food industry.

The Effect of Germination and Fermentation on the Physicochemical, Nutritional, and Functional Quality Attributes of Samh Seeds.

This study investigated the effects of fermentation and germination on the physicochemical, nutritional, functional, and bioactive quality attributes of samh seeds. Regardless of the processing treatment, samh seeds were found to be a rich source of phenolic compounds, namely gallic acid (79.6-96.36 mg/100 g DW), catechol (56.34-77.34 mg/100 g DW), and catechin (49.15-84.93 mg/100 g DW), and they possessed high DPPH antiradical activity (65.27-78.39%). They also contained high protein content (19.29-20.41%), essential amino acids content (39.07-44.16% of total amino acids), and unsaturated fatty acid content (81.95-83.46% of total fatty acids) and a low glycemic index (39.61-41.43). Fermentation and germination increased L*, b*, foaming capacity, oil absorption capacity (OAC), water absorption capacity (WAC), swelling power, microbial counts, antioxidant activity, total flavonoid content (TFC), total phenolic content (TPC), in vitro protein digestibility, protein efficiency ratio, and total essential amino acids and reduced water solubility, emulsion stability, tannin, and phytate contents compared to raw samh seeds (p < 0.05). The highest levels of pH, ash, carbohydrate, fiber, and glycemic index were observed in raw samh seeds, and both germination and fermentation processes reduced these attributes to various degrees (p < 0.05). Germination increased the redness (a*), moisture content, essential and non-essential amino acids, potassium, zinc, phosphorous, stearic acid, and oleic and unsaturated fatty acids and reduced total solids, fat content, iron, zinc, calcium, magnesium, sodium, palmitic acid, and total saturated fatty acids of the samh seeds compared to the raw ones. Fermentation increased the total solid, acidity, fat, protein, calcium, magnesium, sodium, phosphorous, iron, zinc, palmitic acid, and total saturated fatty acids and reduced the a* value, moisture, non-essential amino acids, and total unsaturated fatty acids of the samh seeds compared to the raw ones. In conclusion, samh seeds are a rich source of nutrients that could generally be enhanced by germination and fermentation processes. The reported information facilitates strategies towards the application of these underutilized seeds in foods.

The Extraction and Impact of Essential Oils on Bioactive Films and Food Preservation, with Emphasis on Antioxidant and Antibacterial Activities-A Review.

Essential oils, consisting of volatile compounds, are derived from various plant parts and possess antibacterial and antioxidant properties. Certain essential oils are utilized for medicinal purposes and can serve as natural preservatives in food products, replacing synthetic ones. This review describes how essential oils can promote the performance of bioactive films and preserve food through their antioxidant and antibacterial properties. Further, this article emphasizes the antibacterial efficacy of essential oil composite films for food preservation and analyzes their manufacturing processes. These films could be an attractive delivery strategy for improving phenolic stability in foods and the shelf-life of consumable food items. Moreover, this article presents an overview of current knowledge of the extraction of essential oils, their effects on bioactive films and food preservation, as well as the benefits and drawbacks of using them to preserve food products.