Quality assessment minimally processed immature jakfruit (Artocarpus heterophyllus, Lam.) as affected by pretreatments

Abstract

Degree of browning, firmness, sensory properties and microbiological quality of minimally processed immature jakfruit were investigated on initial and seventh day after storage at 5–7 °C. Samples were pretreated with 0.5 % and 1 % sodium metabisulphite, 1.5 % citric acid + 1.5 % ascorbic acid, 3 % citric acid, 3 % ascorbic acid and packed in polystyrene packages and over wrapped with polyvinylchloride (PVC) stretch film before storage. When degree of browning in relation to absorbance was assessed, immature jakfruit pretreated with 1.5 % citric acid + 1.5 % ascorbic acid showed the lowest absorbance at 420 nm among all pretreated samples indicating low browning in samples. At 450 nm, minimally processed immature jackfruit samples pretreated with 1.5 % citric acid + 1.5 % ascorbic acid showed the highest reflectance (indicating lowest absorbance) compared to other treatments. Variations in firmness were observed after treatment. Microbial counts were within safe-to-consume limits while coliforms were not detected in any of the samples. Erwinia aphidicola and Bacillus subtilis were identified from minimally processed immature jakfruit samples using molecular tools. 1.5 % citric acid + 1.5 % ascorbic acid, 1 % sodium metabisulphite and 3 % citric acid were relatively more successful in retaining acceptable sensory quality of jakfruit even after 7 days of storage. Above pretreatments could be recommended during minimal processing of immature jakfruit meant for local sale in supermarkets where cold storage is available.