Sensory Attributes and Shelf Life Evaluation of an Instant Soup Powder Fortified with Moringa (Moringa oleifera Lam.) Leaves

Abstract

Micronutrient deficiencies cause severe health problems in Sri Lanka as well as in the global context. Moringa oleifera Lam. (Moringa) is a rich source of micro and macro nutrients. Present consumers seek convenience in food preparation. Therefore, a study was conducted to develop an instant vegetarian soup powder containing moringa dried leaf powder. Four moringa soup powder formulae with different moringa leaf powder contents (w/w) viz., 12%, 16%, 20% and 22% were produced. A sensory evaluation was carried out to assess the consumer acceptance for colour, texture, taste, aroma, viscosity, overall acceptability and purchasing intention using a Nine Point Hedonic scale. The sensory attributes of the best treatment were compared with two locally available commercial instant vegetarian soup powders, M1 and M2. The formula with 12% moringa dried leaf powder showed the highest mean scores for all the sensory attributes and was significantly different from other treatments. It also recorded no significant differences in terms of sensory attributes, except for colour and aroma, when compared to M1 and M2. Further, the new soup formula scored higher mean scores, albeit non-significant, than M2 for texture, taste, aroma, overall acceptability and purchasing intention. The shelf life studies during a 12-month storage at ambient conditions (32±2°C, 56±2% RH) in polypropylene primary packages, with Kraft paper bags lined with polypropylene used as secondary package, showed no significant changes in pH (5.30 to 5.48) and moisture content (7.9 – 8.6%) while the microbial contamination was considerably lower (4.7 × 102 CFU g-1 ) than the permitted limit.