EFFECT OF DRYING METHODS AND TEMPERATURE ON THE QUALITY OF APPLE CHIPS AND ITS STORAGE STABILITY

Abstract

Apple (Malus domestica) is High Value Crops (HVC) of mountainous regions of western Nepal. Apple faces the problems due to spoilage loss, poor handling, lack of proper transportation and market. The main aim of this dissertation was to prepare apple chips by using two different pretreatments; blanching in 0.5% Potassium metabisulphite and osmotic dehydration in 40% aqueous glucose. Ten samples were prepared and dried by using different drying methods i.e., cabinet drying, oven drying, and sun drying in varying temperatures of 50°C and 60°C. The samples were coded as A, B, C, D, E, F, G, H, I, and J in the laboratory and packed in LDPE bags. Sensory data were analyzed by two-way ANOVA (no blocking) using GenStat and means were compared using LSD at 5% level of significance based on sensory attributes i.e., appearance/color, flavor, crispiness, and overall acceptability. From sensory evaluation, Sample coded as A (blanched, cabinet dried at 60°C) was found to be superior than rest of the samples. The best product was evaluated for 3 months in terms of moisture, titratable acidity, pH, TSS, Vitamin C, sensory properties and microbial analysis. As the temperature rose, organic acids became more concentrated, which led to a decrease in pH and an increase in titratable acidity. Similarly, because vitamin C degrades at high temperatures, the amount of vitamin C considerably decreased along with TSS during drying. While pH, TSS, and vitamin C dropped throughout observation, moisture and acidity increased. After 90 days of storage, the sensory qualities in terms of color, flavor, crispiness, and overall acceptability were satisfactory, and microbiological analysis indicated that the product was safe for consumption. The price per 100 grams of apple chips was determined to be NRs. 100.26.