Effects of fortified lysine on the amino acid profile and sensory qualities of deep-fried and dried noodles

Abstract

Introduction: Lysine fortification of wheat flour has been used toward reducing protein energy malnutrition in developing countries. Methods: The feasibility of fortifying instant noodles with lysine was evaluated based on sensory qualities and the residual lysine content. Fifty grams of deep-fried and dried instant noodles were fortified with 0.23 and 0.21 g lysine, respectively. The production temperatures used for deep-frying were 165-175°C and for drying, 80-105 °C; these are the temperatures used in the industrial production of both kinds of noodles. Lysine fortification was then performed at the local factories using the commercial production lines and packaging for both types of instant noodles. Both fortified and unfortified deep-fried and dried instant noodles were stored at 50°C under fluorescent light for 2 and 4 months, respectively. Results: The fortified products were tested for residual lysine content and sensory qualities as compared with unfortified noodles. The results show fortified products from the tested processing temperatures were all accepted. After storage, significant losses of lysine were not found in both types of noodles analysed. The lysinefortified noodles had amino acid scores of 102% and 122%, respectively. After 2 months, the sensory quality of fortified deep-fried noodles was still acceptable; however, the dried noodles turned to an unacceptable dark colour. Conclusion: This study shows that it is feasible to fortify deep-fried instant noodles with lysine, though lysine fortification exhibited an undesirable colour in the dried instant noodles after storage.