Spray drying and ultrasonication processing of camel whey protein concentrate: Characterization and impact on bioactive properties.

The production of whey protein concentrates (WPCs) from camel milk whey represents an effective approach to valorize this processing by-product. These concentrates harbor active ingredients with significant bioactive properties. Camel WPCs were spray-dried (SD) at inlet temperature of 170, 185 and 200°C, or Ultrasonicated (US) for 5, 10 and 15 min, then freeze-dried to obtain fine powder. The impact of both treatments on protein degradation was studied by sodium dodecyl sulfate-PAGE and reverse-phase ultraperformance liquid chromatography (RP-UPLC) techniques. Significantly enhanced protein degradation was observed after US treatment when compared with SD. Both SD and US treatments slightly enhanced the WPCs samples' antioxidant activities. The US exposure for 15 min exhibited highest 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity (12.12 mmol TE/g). Moreover, US treatment for 10 min exhibited the highest in vitro anti-diabetic properties (α-amylase and α-glucosidase inhibition), and dipeptidyl-peptidase-IV inhibitory activity among all samples. In addition, the ultrasonication for 10 min and SD at 170°C showed the lowest IC50 values for in vitro anti-hypercholesterolemic activities in terms of pancreatic lipase and cholesteryl esterase inhibition. Conclusively, these green techniques can be adapted in the preservation and processing of camel milk whey into active ingredients with high bioactive properties.

Enhancing functional properties of rice starches through hydroxypropylation for development of reduced-fat white sauces.

Present study investigated the preparation of commonly used white sauce with 50 % less added fat by using 10 % hydroypropylated Irri and Basmati rice starches in the formulation. The sauces incorporated with hydroxypropylated starches exhibited significantly lower gelatinization temperature and time, while the change in maximum viscosity was insignificant. Significantly improved stability at ambient, refrigeration, and freezing temperatures of reduced-fat white sauces was observed whereas change in the taste was insignificant. Basmati hydroxypropylated starch containing white sauce significantly mimicked the sensory properties of full-fat sauces. The hydroxypropyl groups were found to be 1.06 % and 1.16 % for Basmati and Irri hydroxypropylated starches, respectively. These values fall below the specified limit set by the Food and Drug Administration for the food grade hydroxypropylated starches. Significant improvements in peak viscosity, swelling power, solubility, percent transmittance, and water retention capacity were observed after the chemical modification of both rice varieties.

Comparative study on morphological, rheological and functional characteristics of extruded rice starch citrates and lactates.

Two levels of chemically modified starches (starch citrates and lactates) prepared at 20% and 40% w/v concentration was subjected to extrusion to produce pregelatinized starches (PG). Starch citrates and lactates modified at 20% and 40% level were referred as (SC20 and SC40) and (SL20 and SL40), respectively. These PG starches underwent significant structural changes during extrusion as depicted by scanning electron micrographs. Native starches showed lower swelling power and water binding capacity but formed harder gels compared to chemically modified pregels. The dynamic rheology of these polymers (extruded modified starches) suggested visco-elastic property i.e. (G' > G''). Citrates demonstrated higher G' than lactates in both frequency and temperature sweep tests. Stability of storage moduli over entire temperature range confirmed that addition of citrates and lactates led to strengthening of gel structure through cross linking and esterification. Non-newtonian behavior was shown by all samples as determined through steady shear flow test with flow behavior index <1. Starch citrate (SC20-PG) demonstrated higher shear stress values. While, SC40-PG depicted anti-thixotropic behavior as measured through in-shear structural recovery measurements. On the basis of results obtained, the dual modification (chemical followed by extrusion) may impart fruitful applications in various food products.

Characterization and utilization of hydroxypropylated rice starches for improving textural and storage properties of rice puddings.

This work investigated the effect of hydroxypropylation on the physicochemical characteristics of Basmati and Irri rice starches with milk and water. The effect of hydroxypropylated starches on the storage, texture stability and sensory characteristics of rice pudding was studied. Pudding was prepared by replacing 3%, 5% and 10% of Irri rice flour with native and hydroxypropylated starches isolated from two predominant rice varieties of Pakistan; Irri and Basmati. Syneresis was not observed in pudding made with hydroxypropylated starches and native basmati starch. On the contrary, pudding prepared with Irri rice flour and Irri starches showed poor keeping quality. Sensory analysis showed that modification of rice starches did not significantly alter the color, flavor, taste and overall acceptability of pudding. The results suggested that rice pudding, a very popular dessert of South Asia could be prepared with improved storage characteristics using hydroxypropylated starches without altering the taste and acceptability of the product.

Influence of different molar concentrations of acid on morphological, physicochemical and pasting properties of Pakistani Basmati and Irri rice starches.

Starches extracted from two dominant varieties of rice, Basmati and Irri were subjected to acid hydrolysis by preparing starch slurry of 35% (w/v) in HCl solutions of concentrations 0.1M, 0.3M and 0.8M. The scanning electron micrographs showed that granular morphology of starches significantly changed after acid hydrolysis. Acid thinning improved the solubility of starches whereas decline was observed in swelling power and water retention capacity. Paste clarity of both acid treated Basmati and Irri rice starches reduced gradually upon cold storage. Also reduction in values of pasting, peak viscosity, hot paste viscosity, cold paste viscosity and set back were observed in acid thinned Basmati and Irri rice starches. The DE values increased with the increase in HCl concentration for both Basmati and Irri starch. The hardness of 0.8M HCl treated Basmati starch gel was found significantly lower than all treated and untreated starches. The gelatinization enthalpy for Basmati starch significantly reduced after acid hydrolysis with 0.1M, 0.3M and 0.8M HCl solutions at p <0.05.

Effect of succinylation on functional and morphological properties of starches from broken kernels of Pakistani Basmati and Irri rice cultivars.

Starch extracted from broken kernels of Basmati and Irri rice varieties of Pakistani rice were subjected to modification by addition of succinic anhydride at levels of 2%, 4% and 5% based on dried weight of starch. The succinyl content of Irri rice starch increased with the concentration of succinic anhydride. Scanning electron micrographs revealed presence of dents and fusion of rice starch granules. Swelling power and water retention capacity (WRC) significantly improved after succinylation while on refrigerated storage percent decline in paste clarity of modified rice starches was stable as compared to native Basmati (BC) and Irri (IC) rice starches. Succinylation also reduced solubility, pasting temperature (PT) and gel hardness of starch gels. Improvement was observed in cold storage stability of rice starch succinates as evident from textural profile analysis.