Impact of different factors on the yield and properties of fractions enriched in dietary fiber isolated from peach (Prunus persica L.) residues

Abstract

The industrialization of peaches gives origin to leftover remaining from fruit canning, juice or jam production. The transformation of leftover to dietary fiber (DF) concentrates represents a strategy that can be incorporated in productive processes tending to optimize raw material use. In the present research, DF was obtained from peach (Prunus persica L.) using an ethanol treatment followed by dehydration. The influence of four factors: time and temperature of ethanol treatment prior to drying step, ratio of ethanol to sample and drying temperature using microwave or convective drying on different properties (yield, hydration properties, oil holding capacity and apparent density) of the concentrate obtained, were studied through a two level orthogonal design. Yield ranged between 4.38-7.27 g/100g for all the conditions explored. Time and temperature of the ethanol extraction affected properties when a subsequent convective drying was employed. The effect of the ethanol/sample ratio and of the temperature of drying on oil holding capacity and hydration properties was mainly detected on samples dried by microwave technique. The results obtained provide insight into the effect of processing of plant residues on the properties of DF concentrates obtained and on their potential performance as ingredients or additives for the food industry. It could be concluded that the drying technique is a key factor in relation to the properties of dietary fiber enriched fractions isolated from peach. Microwave drying allowed to produce fractions with functional properties that can be modulated through the use of different relations of ethanol to sample ratio and drying temperatures.