Chocolate Coating Effect on Whey Protein Isolate-Pullulan-Coated Freeze-Dried Chestnut

摘要

Chestnuts are characterized by a limited shelf-life because of their high water content and sugar content hence producers around the world are confronted with a storage problem as product losses are very high. The strategy of the conception, stemming from the current adoption of new food technologies combined with the consumer desirability to put to shelf new products on the market has made researchers and industrialists to upgrade and/or add value to the existing products in order to provide a wider choice of new products to the consumer disposal. The objective of this work was to come up with a suitable technology of extending the shelf-life of harvested chestnut fruits and to develop a new food product for commercial consumption. Whey protein isolate–Pullulan-coated roasted and freeze-dried chestnut (WPI–Pul-RFDC) was coated separately with dark chocolate (DCC) and milk chocolate (MCC). Color change of surface coating and decay incidence were studied at [7°C, 82 ± 5% RH] and [25 ± 2°C, 30 ± 2% RH] for 6 months storage. Further investigation on sensory evaluation were carried out using a taste panel of 120 consumers. 7°C and 25°C provided the best storage conditions for dark chocolate and milky chocolate coating respectively. The results obtained were effective in the control of overgrowth of spoilage organisms and surface discoloration, which is satisfactory in improving the quality and increasing the shelf-life of chestnut. The consumer acceptance testing revealed that chocolate-coating greatly improved the sensory attributes of chestnut as compared to the WPI-Pul coated sample acceptance. This is an alternative strategy to add value to chestnut thus minimizing the significant losses in harvested fruits hence providing a wider choice of new products to the consumer disposal.