Moisture Sorption Isotherms of Yogurt Powder Containing Candied Chestnut Puree

Abstract

Yogurt powder was produced by freeze drying and with added candied chestnut puree at ratios of 5, 10, and 20 % by weight. Moisture sorption isotherms of yogurt powder samples, plain (YP), and containing 5, 10, 20% candied chestnut puree (CCP) were determined at 25°C using the standard, static-gravimetric method. The experimental adsorption data of yogurt powders at 25°C were fitted to 14 sorption equations which are most widely used to fit experimental sorption data of various food materials. The parameters of the sorption models were estimated from the experimental results by using the nonlinear regression analysis. The GAB model gave the closet fit to the sorption data of freeze dried yogurt powders with candied chestnut puree at 25°C. BET, Ferro Fanton, Henderson, Halsey, Oswin and Modified Oswin models are also acceptable for describing the adsorption isotherms for freeze dried yogurt with candied chestnut puree at 25°C.

Powdered yoghurt produced by spray drying and freeze drying: a review

“…The authors used the parameter of moisture to calculate the product shelf life, and concluded that moisture levels from 6.8% to 7.2% were decisive for product quality, since higher values led to particle agglomeration. In addition, it is worth mentioning that darkening is common under inadequate storage conditions, with the development of off-tastes due to the formation of insoluble compounds from the Maillard reaction (ZARE et al, 2011). Wang et al (2004) analysed soy yoghurt powder stored in glass, polyethylene terephthalate (PET) and laminated packages at 4 °C.…”

“…Yoghurt powder could be used as an ingredient or supplement in juices, biscuits, ice cream, candies and milk beverages, besides replacing milk powder in recipes, hence adding nutritional and functional values to these products MISHRA, 2004b;TAMIME;ROBINSON, 2007;ZUNGUR BASTIOĞLU et al, 2016).…”