Author : Curayag, Queenie Ann L.

Summary : The physicochemical, functional and nutritional properties of purple-fleshed sweet potato (PSP) as affected by different pre-drying and drying conditions and its utilization in candies, muffins and breads were studied. Among the four PSP varieties that were screened, Haponita had the highest dry matter content (39.14%), iron (19.13 mg/100 g) and zinc (0.80 mg/100g) content and antioxidant activity (74.22%) and was chosen as the best variety. The different pre-drying treatment and drying temperatures and drying time significantly affected the physicochemical, functional and nutritional properties of PSP. Steaming process increased the antioxidant activity of raw PSP by 28.56% and produced purple sweet potato flour (PSPF) with intense color attributes, higher TSS, WAI, WSI, SWC and antioxidant activity compared to other pre-drying treatments. Drying of steamed PSP at 60°C for 9 and 11 hrs and at 70°C for 7 hrs produced steamed PSPFs with better physicochemical abd functional properties, antioxidant activity and phytochemical components. A minimum of 40% PSPF substitution in candies, 40 to 50% in muffins and 20 to 30% in bread greatly improved its qualities and its corresponding acceptability to the panelists. The chemical composition of PSP generally decreased after processing into flour and utilization in candies, muffins and breads. In terms of nutrient contribution, raw PSP and steamed PSPF are good sources of energy, iron and zinc. PSPF-substituted candies are good sources of energy while muffins and breads are potential sources of energy, protein and iron. Wheat flour-based products like muffins and breads can still be considered as high sources of energy, protein and iron even when substituted with steamed PSPF. However, it is not very practical because of large financial requirements. To improve fishers' compliance in the study area there is a need to use other determinants of compliance such as morality and social influence factors. In Indonesia and the Philippines, enforcement institutions are not as well established as in Malaysia. Therefore, institutions of enforcement should be given priority in Indonesia and the Philippines. In Malaysia a fairly well developed enforcement institutions exists, thus in this case there is a need to enhance the scheme and implement enforcement more effectively. To improve compliance, fisheries management authorities should also explore alternative approaches for managing fisheries. One such approach is the co-management approach.