Effects of Steaming, Boiling, and Roasting on Physicochemical Quality, Lipase Activity, Textural Properties, and Microstructure of Jackfruit (A. heterophyllus) Seeds

Abstract

This study investigated the effects of three processing methods, including steaming, boiling, and roasting, on the physicochemical quality, sensory properties, lipase activity, and microstructure of jackfruit (Artocarpus heterophyllus) seeds using various analytical techniques. Our results showed that both steaming and boiling resulted in higher sensory scores for hardness (7 and 7, both moderately soft), colour (8 and 9, both light yellow), texture (8 and 5, less than 10% and 40% crack open), and smell (7 and 5, mildly sweet fragrance and musty scent) compared to the roasting (all p < 0.05). Although steaming was particularly effective in preserving the original colour of the raw jackfruit seeds with the lowest ΔE of 5.72, boiling maintained better colour attributes with higher lightness and yellowness values (90.75 and 8.37). Analysis of textural properties showed that steaming, boiling, and roasting led to a moderate reduction in hardness and springiness compared to raw samples (all p < 0.05), which are favorable for jackfruit seeds because it resulted in a tender texture with a subtle bounce when bitten. Roasting also yielded partially gelatinized seeds (lower gelatinization compared to boiling and steaming, p < 0.05) that maintained a balance between firmness and tenderness and presented with a pleasant bite with a slight crunch. In addition, roasted jackfruit seeds demonstrated the greatest capacity to inhibit lipase activity (all p < 0.05), an enzyme essential for fat digestion and absorption, highlighting their significant potential for use as a weight loss supplement. Principal component analysis of 22 different factors ranked the overall quality of processed jackfruit seeds in the following order: roasting > steaming > boiling. In conclusion, roasting, compared to steaming and boiling, is recommended for jackfruit seed processing in the culinary industry because it yields an ingredient with the best physicochemical quality, lipase inhibition activity, textural properties, and microstructure.