HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by White, C. H. Articles by Marshall, R. T. Search for Related Content PubMed Articles by White, C. H. Articles by Marshall, R. T.

Reduction of Shelf-life of Dairy Products by a Heat-stable Protease from Pseudomonas Fluorescens P26¹

Food Science and Nutrition Department, University of Missouri, Columbia 65201

ABSTRACT

Butter, Cheddar cheese, cottage cheese, vanilla ice cream mix, and homogenized milk were manufactured from milk or components of milk containing heat-stable protease or a culture of Pseudomonas fluorescens P26 which produces this protease. Effects of protease on keeping quality were determined by comparisons to controls without protease. Comparisons were on results of the Hull test for measurable proteolysis and, also, on sensory analyses by panel evaluations. No significant differences in quality were observed on butter, ice cream mix, or milk which was repasteurized at 63 C for 30 min. Protease (or bacteria) was added 12 h before manufacture. Proteolysis was significant in Cheddar cheese made from milk containing .94 unit of enzyme per milliliter. Flavor scores were significantly lower in cheese made from milk containing the protease than in the control cheese. The protease (.86 unit/ml) produced significant proteolysis in cottage cheese but not as much as P. fluorescens P26. Flavor was adversely affected by both treatments.

¹ Contribution from the Missouri Agricultural Experiment Station. Journal Series No. 6556. Approved November 17, 1972.

² Present address: Department of Dairy Science, University of Georgia, Athens 30601.