Advancement in fruit drying through the analysis of moisture sorption isotherms: processing effects on Australian native fruits in comparison to apple

Abstract

Australian native fruits are well-adapted to local climate and have growing interest in their nutritional and sensory qualities. Among the most highly produced are finger limes and muntries. However, published literature on their characterisation and especially their processing is limited. Water binding in foods is linked to their preservation through the amount of water microbes need to be active and the drying energy required. How processing affects this binding, however, is poorly understood. This work studied the water binding of apples compared with muntries and finger limes. Unlike in apple, water binding in native fruits was observed to increase after drying. This was correlated to increased breakdown of complex carbohydrates into simple sugars in native fruits. It is suggested this may be a feature of their drought adaptation. Together with a newly proposed equation for the drying heat required, these findings can guide more sustainable processing of Australian native fruits.