The effect of maturity,sunburn and the application of sunscreens on the internal and external qualities of pomegranate fruit grown in Australia

Consumer interest in pomegranate fruit (Punica granatum L.) is increasing in Australia as a result of its unique external and internal qualities. This work looked at the effect of applying sunscreen treatments to pomegranate fruit on the degree of sunburn damage and the effect of maturity and sunburn on the internal antioxidant concentration of the juice. The pomegranates, cultivar ‘Wonderful’ were grown in Condobolin, New South Wales, Australia.     

Leaf litter decomposition in an upper montane rainforest in Sri Lanka

In a field study in an upper mountain rain forest in Sri Lanka leaf litter decay rates for nine tree species were measured using the standard litterbag method. The leaf species showed a wide variation in decomposition rates with k values ranging from 0.19 to 9.6 (t_0.99 values ranging from 0.5 to 24 years), but it was possible to recognize fast, medium and slow decomposition groups. While there were considerable differences in physical and chemical litter properties these were poor predictors of decomposition rates. There was considerable variation in the N, P and lignin contents of mature green leaves and freshly fallen dead leaves of the different tree species. Percent resorption of N varied from 0 (one species) to 56 and of P from 0 (three species) to 73. There were no consistent patterns of nutrient mobilization and net release of N and P in the five leaf litter species studied.     

Tocopherol and ascorbate have contrasting effects on the viability of microencapsulated Lactobacillus rhamnosus GG

The antioxidants, sodium ascorbate and tocopherol, have contrasting effects on the viability of microencapsulated Lactobacillus rhamnosus GG (LGG) spray-dried powders during storage (4 and 25 °C; 32, 57, and 70% relative humidity). The addition of tocopherol improved probiotic viability during storage, while the incorporation of Na-ascorbate alone or in combination with tocopherol had detrimental effects on probiotic survival. The beneficial effect of tocopherol is a consequence of its chemical antioxidative action. The reduced viability in Na-ascorbate containing microcapsule formulations is hypothesized to be due primarily to the production of acetic acids arising from chemical degradation reactions and the catabolism of ascorbate by LGG. This study highlights the importance of considering the detrimental consequences of degradative chemical reactions and the metabolic fate of additives on the viability of probiotics when designing probiotic encapsulant formulations.     

Food matrix effects on in vitro digestion of microencapsulated tuna oil powder

Tuna oil, containing 53 mg of eicosapentaenoic acid (EPA) and 241 mg of docosahexaenoic acid (DHA) per gram of oil, delivered as a neat microencapsulated tuna oil powder (25% oil loading) or in food matrices (orange juice, yogurt, or cereal bar) fortified with microencapsulated tuna oil powder was digested in simulated gastric fluid or sequentially in simulated gastric fluid and simulated intestinal fluid. The level of fortification was equivalent to 1 g of tuna oil per recommended serving size (i.e., per 200 g of orange juice or yogurt or 60 g of cereal bar). The changes in particle size of oil droplets during digestion were influenced by the method of delivery of the microencapsulated tuna oil powder. Lipolysis in simulated gastric fluid was low, with only 4.4-6.1% EPA and ≤1.5% DHA released after digestion (as a % of total fatty acids present). After sequential exposure to simulated gastric and intestinal fluids, much higher extents of lipolysis of both glycerol-bound EPA and DHA were obtained (73.2-78.6% for the neat powder, fortified orange juice, and yogurt; 60.3-64.0% for the fortified cereal bar). This research demonstrates that the choice of food matrix may influence the lipolysis of microencapsulated tuna oil.