Juice Processing Lab Report

ABSTRACT

Two groups of apples were washed, weighed and pulped through a juice extractor. One group received treatment with ascorbic acid, which was then followed by both groups being divided into a further 2 groups. All four groups received treatment with potassium metabisulphite, and then one group of ascorbic treated apple juice and one group of non ascorbic treated apples had the enzyme pectinase added them. All four samples were put into cylinders then stored at 25 °C and after one week results were recorded. This procedure was also completed by different lab groups except it was stored at 2°C.

Ascorbic acid treatment resulted in the juice maintaining its colour and appearance because of its antioxidant qualities and enzymatic treatment using pectinase resulted in a clearer juice due to the breakdown of the pectin. Temperature was found to also have an affect on the clarity of the juice as well as the activity of the enzyme pectinase. Pectinase works more effectly at higher temperatures because there is more kinetic energy involved causing the pectin and the pectinase to combine.

INTRODUCTION

This experiment was performed to examine the effects certain clarification processes have on juice quality as well as examine the effects of antioxidant treatment in juice processing.

Processed fruit juices have become an important part in peoples diet both in australia and worldwide and represents a major part in the juice processing industry. Juice products are being marketed as refrigerated, shelf-stable, and frozen, in a variety of packages with increased emphasis on functionality, health attributes, new flavors or blends, and in some cases fortified with vitamins and minerals (McLellan and Padilla-Zoikour 2005).

Processed products such as apple juice can be either single strength or bulk concentrate and are available either as clarified or cloudy juice (Lozano 2006). apple juice contains a considerable proportion of the soluble components of the original...