Determination of a thermal process schedule for guava (Psidium guajava Linn.).

Nath, N. and Ranganna, S. (1983) Determination of a thermal process schedule for guava (Psidium guajava Linn.). Journal of Food Technology, 18 (3). 301-316, 27 ref..

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Abstract

A thermal process schedule for guava canned in syrup was evolved on the basis of inactivation of pectinesterase (PE) which was found to be more heat resistant than peroxidase. Values for thermal inactivation and thermal resistance of PE in syrup homogenate containing guava pulp and sugar syrup in the ratio of 11:6 and total soluble solids content of 20% at pH 4.0 were F [29.22; 205.1] = 1.0 and D [29.81; 205.1] = 0.592, resp. The F value of 1 was equivalent to 1.69 D. In commercial canning, a 2.5 D process is recommended, which ensures a microbiologically safe and organoleptically acceptable product. Process time was calculated both by graphical and formula methods. Calculation by the formula method using slopes of heating and cooling curves plotted on semilog paper by least squares analysis, and fh/U:g [Sterilization in Food Technology (1957) by Ball + Olson, McGraw-Hill Book Co., New York] tables for actual values of jc gave process times very close to those obtained by the graphical method. Process times required at different initial and processing temp. are given. To minimize viscosity increase in the covering syrup during storage, firming of guava in 1% CaCl2 solutions for 30 min prior to canning is suggested. In addition, use of covering syrup containing 0.125% ascorbic acid with or without citric acid (0.06%) yields a product of good colour, texture and flavour.

Item Type:	Article
Uncontrolled Keywords:	THERMAL-PROCESSES; guava-in-syrups, thermal processing of canned; CANNING-; CANNED-FOODS; FRUITS-SPECIFIC; PECTIC-ENZYMES; guava-in-syrups, pectinesterases inactivation in canned
Subjects:	600 Technology > 08 Food technology > 24 Fruits 600 Technology > 08 Food technology > 06 Preservation and Storage
Divisions:	Fruit and Vegetable Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	25 May 2016 07:39
Last Modified:	25 May 2016 07:39
URI:	http://ir.cftri.res.in/id/eprint/6697

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