Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Development of Two Types of Isotonic Beverages with Functional Attributes Using Natural and Synthetic Ingredients(Faculty of Science, University of Peradeniya, Sri Lanka, 2024-04-23) Kariyawasam KP; Somaratne GM; Roy D; Silva DD; Weththasinghe WAOW; Sandanika DWNIsotonic 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.Item The Hydrating Effects of Hypertonic, Isotonic and Hypotonic Sports Drinks and Waters on Central Hydration During Continuous Exercise: A Systematic Meta-Analysis and Perspective(Springer Nature, 2022-02) Rowlands DS; Kopetschny BH; Badenhorst CEBackground Body-fluid loss during prolonged continuous exercise can impair cardiovascular function, harming performance. Delta percent plasma volume (dPV) represents the change in central and circulatory body-water volume and therefore hydration during exercise; however, the effect of carbohydrate–electrolyte drinks and water on the dPV response is unclear. Objective To determine by meta-analysis the effects of ingested hypertonic (> 300 mOsmol kg−1), isotonic (275–300 mOsmol kg−1) and hypotonic (< 275 mOsmol kg−1) drinks containing carbohydrate and electrolyte ([Na+] < 50 mmol L−1), and non-carbohydrate drinks/water (< 40 mOsmol kg−1) on dPV during continuous exercise. Methods A systematic review produced 28 qualifying studies and 68 drink treatment effects. Random-effects meta-analyses with repeated measures provided estimates of effects and probability of superiority (p+) during 0–180 min of exercise, adjusted for drink osmolality, ingestion rate, metabolic rate and a weakly informative Bayesian prior. Results Mean drink effects on dPV were: hypertonic − 7.4% [90% compatibility limits (CL) − 8.5, − 6.3], isotonic − 8.7% (90% CL − 10.1, − 7.4), hypotonic − 6.3% (90% CL − 7.4, − 5.3) and water − 7.5% (90% CL − 8.5, − 6.4). Posterior contrast estimates relative to the smallest important effect (dPV = 0.75%) were: hypertonic-isotonic 1.2% (90% CL − 0.1, 2.6; p+ = 0.74), hypotonic-isotonic 2.3% (90% CL 1.1, 3.5; p+ = 0.984), water-isotonic 1.3% (90% CL 0.0, 2.5; p+ = 0.76), hypotonic-hypertonic 1.1% (90% CL 0.1, 2.1; p+ = 0.71), hypertonic-water 0.1% (90% CL − 0.8, 1.0; p+ = 0.12) and hypotonic-water 1.1% (90% CL 0.1, 2.0; p+ = 0.72). Thus, hypotonic drinks were very likely superior to isotonic and likely superior to hypertonic and water. Metabolic rate, ingestion rate, carbohydrate characteristics and electrolyte concentration were generally substantial modifiers of dPV. Conclusion Hypotonic carbohydrate–electrolyte drinks ingested continuously during exercise provide the greatest benefit to hydration.Item Collagen dehydration(Elsevier BV, 1/09/2022) Haverkamp RG; Sizeland KH; Wells HC; Kamma-Lorger CType I collagen is a ubiquitous structural protein in animal tissues. It is normally present in a hydrated form. However, collagen is very dependent on associated water for its mechanical properties. In skin, where type I collagen is dominant, there is a longstanding concern that the skin and therefore collagen may partially dry out and result in structural degradation. Here we show that dehydration of type I collagen fibrils, using 2-propanol, results in a two-stage dehydration process. Initially, the fibrils do not change length, i.e. the D-period remains constant, but shrinkage occurs within the fibrils by an increase in the gap region and a decrease in the overlap region within a D-band and a shortening of the helical turn distance and fibril diameter. Only with further dehydration does the length of the collagen fibril decrease (a decrease in D-period). This mechanism explains why collagen materials are resistant to gross structural change in the early stages of dehydration and shows why they may then suffer from sudden external shrinkage with further dehydration.