Shelf-life of pumpkin-blended products, flour and fruit slices of different presentation formats

Abstract

Pumpkin has high potential of generating income and overcoming food insecurity. Today’s consumer looks upon the food industry to provide healthy, attractive convenience products that remain wholesome for long. However, spoilage of horticultural produce results due to improper handling and microbial attack. Microbial spoilage is the major factor limiting shelf-life of fresh produce and processed products. It arises from improper handling and spore contamination, leading to economic loss. The objective of the present study was to determine whether shelf-life of value-added pumpkin products could be prolonged by wrapping, drying, or processing. The study used products in three experiments: (1) pumpkin fresh fruit (presented as whole, half slices or quarter slices plus or minus clear shrink wrap); (2) pure flour (dried using oven, enhanced solar, or open sun); and (3) bakery products (cake, cookies, scones, mandazi, bread, porridge, chapatti or irio blended with 0%, 5%, 20%, 50% or 90% pumpkin flour). All experiments were conducted in completely randomized design, replicated four times and repeated once. Pooled average data values were subjected to analysis of variance and significantly different means were separated using the least significantly difference test at α = 0.05. Plate Count Agar and Potato Dextrose Agar were used to determine total viable counts and fungi, respectively, on pumpkin fresh fruit, dried flour and blended products, while MacConkey Agar was used to assess enteric bacteria in dried flour and blended products. Results showed significant differences (P<0.0001) in shelf-life of flour from the three drying methods. Enhanced solar dried flour had longest shelf-life of 11.5 months. Bacilli were the dominant bacteria in fresh fruit slices, while flour had bacilli and cocci, which were also dominant in blended products. Significant difference (P<0.0001) occurred in moisture content of cake, mandazi and scones with various flour-blending levels. Cookies had the longest shelf-life of 64 days, while irio, chapatti and porridge got spoilt after two days. Significant differences occurred in microbial counts of the various flour-blended products throughout the storage periods. Baked products with up to 20% pumpkin flour-blend had great potential of remaining wholesome for longest storage period and hence are recommended for adoption.