Novel food gelling agent as a coating material on blueberries : A Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University

Abstract

The objective of this study was to see the efficacy of novel gel as a good coating material on blueberries. Blueberries are highly perishable and edible coating as an alternative technique is used as it reduces the transpiration and respiration rate, maintains colour and texture and delayed fruit maturation. The novel gel was made from disodium guanylate (DG) and citric acid (CA). The parameters that were investigated during this study included weight loss, surface colour, texture, pH and total soluble solids. Three treatments were followed: (A) Fruit washed with distilled water as a control, (B)1M citric acid+ 0.25M disodium guanylate+ 1% glycerol, (C) 1M citric acid+ 0.25M disodium guanylate. The results were observed on the 0th day, 7th day and 14th day. The blueberry coated samples did not a show significant difference in weight loss, firmness, pH with the control group. The TSS showed a significant difference between coated blueberries and control. The TSS value of control berries was increasing with storage time than coated samples. The colour indexes showed few significant differences among treatments and storage time. However, the colour change was highly dependent on the storage time rather than the type of treatments. The novel gel as a coating material needs modification to be effective coating material.