This study investigated the impact of extraction pH (pH 7-11) on the yield, composition, protein profile and properties of quinoa protein isolate (QPI), including solubility, interfacial tension and heat-induced aggregation. Extraction pH considerably influenced protein yield, purity and solubility, with alkaline conditions promoting higher protein yield (from 27.4 % to 39.5 % as extraction pH increased from pH 7 to pH 11) but lower purity (from 89.7 % to 85.1 %) owing to the co-precipitation of carbohydrates. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis combined with liquid chromatography with tandem mass spectrometry revealed major protein profile in quinoa protein, confirming the abundance of 11S globulin. Moreover, extraction pH affected the solubility over a broad range of pH, interfacial properties and heat-induced aggregation behaviour of QPI. QPI extracted at pH 9 exhibited better solubility and better interfacial tension reduction capability but lower heat stability compared with QPI extracted at pH 11. Results from this study provided useful information and essential insights into the utilisation of quinoa proteins in various food applications.

Isotonic drinks maintain a balance of salt and sugar concentrations similar to that of the human body, aiding in the rapid replacement of lost fluids during dehydration. Although the availability of isotonic beverages in the Sri Lankan market is limited, this segment is experiencing rapid growth on the global stage, with numerous brands marketing their products. Moreover, it is especially advantageous to create isotonic beverages tailored to tropical country consumers, given their ability to effectively replenish lost fluids due to dehydration. This study seeks to develop economically viable and commercially feasible formulations of isotonic drinks that cater to the preferences of Sri Lankan consumers, utilizing a combination of synthetic and natural ingredients. In the realm of natural isotonic beverages, coconut water and bee honey serve as excellent sources of electrolytes and sugar, respectively. Following osmolality and sensory evaluations, the chosen samples underwent further analysis to determine their mineral content and physicochemical characteristics. These developed formulations fall within the prescribed ranges for osmolality (270-330 mOsm/kg) and sodium content (460-1150 mg. L-1), aligning with international standards for isotonic beverages. In conclusion, the devised formulas successfully adhere to international specifications for isotonic beverages. The abundant potential of coconut water and bee honey in Sri Lanka with wide availability as valuable sources of minerals and energy for crafting isotonic drinks is evident.

Digestion in the small intestine is a crucial step in the breakdown and absorption of nutrients from human milk. In vitro models of intestinal digestion are commonly employed to investigate the digestion behaviour of breast milk nutrients. Accurate replication of the infant small intestine requires a detailed understanding of its biochemical environment. This review summarises current knowledge on small intestinal digestion in infants, integrating evidence from both human studies and in vitro intestinal digestion models. Key challenges in simulating the infant small intestinal conditions, including motility, intestinal fluid dynamics and composition, enzymatic activity, and absorption are discussed. This literature review also provides recommendations for enhancing the physiological relevance of in vitro small intestinal digestion systems for studying intestinal digestion in early infancy.