Water activity depression of tejocote fruit (crataegus pubescens) using osmotic solutions and pressure gradients

Abstract

Tejocote is a native fruit to Mexico. Peeled tejocote is commonly preserved by cooking it in sucrose solutions and packed in hot sterilized jars. Such process involves moisture removal and solute impregnation, whose overall effect reduces water activity of the product. The objective of this work is to determine the effect of syrup concentration and processing time on aw of osmodehydrated tejocote, at ambient temperature. Peeled tejocote was subjected to dehydration impregnation with vacuum pulse of 50 cmHg for 3 min and 0.5–5 days of immersion in sucrose solutions (30–50 %), using the response surface methodology. A significant model (p < 0.01) was obtained to describe aw of osmodehydrated tejocote, as a function of the studied variables. Important aw depression was achieved (0.930) after 3 days of processing. Studied osmotic dehydration conditions allowed to reduce aw of peeled tejocote, to levels that would enhance its stability.