No abstract

This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Factors affecting milk clotting activity of rennet substitute extracted from green bracts of artichoke (Cynara scolymus) flowers in different buffer solutions were evaluated. These factors include extraction pH, clotting temperature, extract concentrations, addition of CaClR 2 R, NaCl and glucono delta-lactone (GDL) at different concentrations. The proteolytic activity of different extract solutions and rheological properties of produced curd was studied as well. The obtained results indicated that the optimum clotting activity of artichoke crude extracts improved water holding capacity and susceptibility to syneresis obtained at pH value of 5.0-6.0, temperature of 65-70°C and 3%, 0.04-0.05, 3%, 0.5% of crude extract, CaClR 2 R, NaCl and GDL concentrations, respectively. The optimum clotting activity of artichoke crude extracts indicated that the sodium acetate buffer solution T4 (5% NaCl in sodium acetate buffer, pH 5.0) and sodium phosphate buffer, T5 (5% NaCl in sodium phosphate buffer, pH 5.5), T6 (5% NaCl in sodium phosphate buffer, pH 6.5), and T7 (5% NaCl in sodium phosphate buffer, pH 7). Results also indicated that artichoke crude extracted in sodium phosphate buffer solutions and sodium acetate buffer (T4) had higher proteolytic activity than other buffers. The best rheological properties of resultant curds were noticed in sodium phosphate buffers (T5, T6, T7) and sodium acetate buffer (T4).

This study was designed to evaluate some properties of fruit yoghurts made with adding carrot and guava pulp during storage. The obtained results revealed that, the pH was decreased by time of storage while acidity was increased in all types of drinking yoghurt. Adding of 10, 15 and 20% guava pulp in yoghurt increased significantly (p<0.05) the total phenolic compounds (TPC), antioxidant activity (AA), fiber content and ascorbic acid (Vitamin c). The rheological and sensory properties of yoghurt were improved comparing to the control samples, While the protein content, pH value and syneresis decreased significantly (p<0.05) than control samples. On the other hand, Addition of 10, 15 and 20% carrot pulp to yoghurt increased (TPC), (AA), ascorbic acid and fiber content, while the protein content, pH value decreased. Along the storage period of all treatments, the TS, acidity, synersis and viscosity increased significantly, while the pH value, ascorbic acid, acetaldehyde content, AA,TPC were decreased significantly.

In this study, functional yoghurt beverages were fortified with different sorts of carrot products including of 5% fresh carrot pulp (FCP), carrot treated with instant controlled pressure drop (CDIC), and carrot treated with conventional hot air drying (CHAD). The different treatments were analyzed for physicochemical, rheological, microbiological, and organoleptic properties when fresh and after 10 and 20 days of storage at 4±1 °C. Total solids, protein, fat, and ash contents were found to be higher in carrotyoghurt beverages as compared to the control. In addition, there was a gradual decrease in total phenolic contents and antioxidant activities during storage period. Furthermore, the treatments supplemented with CDIC and CHAD exhibited higher water holding capacity. The addition of carrot products had a positive impact on the starter culture bacteria. The viable probiotic cell count throughout the product shelf-life was above the minimum count required in a probiotic product (more than log 6 CFU/g) for treatments containing CDIC and CHAD. However, CDIC and FCP gained the highest scores for the overall sensory attributes.

Anthocyanin have been used as a natural food colourant and as a source of natural antioxidants. Aqueous extracts of dried roselle calyces, outer peels of yellow onions, and peanut skins were used as sources of anthocyanin and other functional components such as phenolic and flavonoid compounds to fortify yoghurt beverages. Antioxidants, total phenolics, total flavonoids and anthocyanin were estimated in the plant extracts. Colour stability was evaluated in yoghurt beverages fortified with anthocyanin extracted during the storage period at 4±1°C for three weeks. The highest amount of total phenolic content was observed in peanut skin extract (1.645 mgml -1 ), followed by dry outer peels of onions (1.5 mgml -1 ) and roselle calyces (1.3 mgml -1 ). Dry outer peels of onions showed the highest flavonoid content compared with peanut skin and roselle calyces extract. The highest amount of total anthocyanin was observed in roselle calyces (3.877 mg 100 g -1 ), followed by aqueous extract of onions skin (0.635 mg 100 g -1 ). During the storage period at 4±1 °C for three weeks, yoghurt beverages physicochemical and functional properties had been evaluated. The anthocyanin improved the colour, appearance, and overall acceptability of fortified yoghurt beverages. The overall results suggested that it is possible to produce high-quality yoghurt beverages fortified by adding 0.2% extracts of dry peanut skins, dry roselle calyces, and dry outer peels of yellow onions, which obtaining colours degree of red-orange, cheery red, and orange-yellow, respectively, colour stability during the storage period at 4±1°C for three weeks.

No abstract

Borage seed oil (BSO), peppermint oil (PO) and lycopene (LC) have accomplished a lot of interest due to their therapeutic benefits in the food and pharmaceutical sectors. However, their employment in functional food products and dietary supplements is still precluded by their high susceptibility to oxidation. Thus, the encapsulation can be applied as a promising strategy to overcome these limits. In the present study, doubly layered water/oil/water (W/O/W) nanoemulsions were equipped using purity gum ultra (PGU), soy protein isolate (SPI), pectin (PC), whey protein isolate (WPI) and WPI-PC and SPI-PC complexes, and their physico-chemical properties were investigated. Our aim was to investigate the influence of natural biopolymers as stabilizers on the physicochemical properties of nanoemulsified BSO, PO and lycopene thru W/O/W emulsions. The droplet size of the fabricated emulsions coated with PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 156.2, 265.9, 254.7, 168.5, 559.5 and 656.1 nm, correspondingly. The encapsulation efficiency of the entrapped bioactives for powders embedded by PGU, WPI, SPI, PC, WPI-PC, and SPI-PC was 95.21%, 94.67%, 97.24%, 92.19%, 90.07% and 92.34%, respectively. In addition, peroxide and p-anisidine values were used to measure the antioxidant potential of the entrapped bioactive compounds during storage, which was compared to synthetic antioxidant and bare natural antioxidant. The collected findings revealed that oxidation occurred in oils encompassing entrapped bioactive compounds, but at a lower extent than for non-encapsulated bioactives. In summary, the findings obtained from current research prove that the nanoencapsulation of BSO surrounded by innermost aqueous stage of W/O/W improved its stability as well as allowed a controlled release of the entrapped bioactives. Thus, the obtained BSO-PO-based systems could be successfully used for further fortification of food-stuffs.