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A comparison of juice extraction methods in the pungency measurement of onion bulbs
Author(s) -
Yoo Kil Sun,
Lee Eun Jin,
Hamilton Brian K,
Patil Bhimanagouda S
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7192
Subject(s) - pungency , pyruvic acid , chemistry , maceration (sewage) , food science , water content , extraction (chemistry) , lactic acid , cultivar , chromatography , horticulture , biology , biochemistry , materials science , bacteria , geotechnical engineering , pepper , engineering , composite material , genetics
BACKGROUND Onion pungency is estimated by measuring the pyruvic acid content in juice extracted from fresh tissues. We compared pyruvic acid content and its variation in the juices extracted by the pressing, maceration, blending with no water, or blending with water (blend/water) methods. RESULTS There were considerable differences in the pyruvic acid content and coefficient of variation ( CV ) among these methods, and there was an interaction between the onion cultivars and the juice extraction methods. The pressing method showed over 30% CV in the quartered or composite samples. The blend/water method showed the greatest pyruvic acid content in the shortday‐type (‘ TG1015Y ’ and ‘Texas Early White’) onions, while the pressing method showed the greatest pyruvic acid content in the longday‐type onions. The blend/water method, which gave ratios between 1:1 and 1:4 (w/w), showed the same pyruvic acid content. The blending (no water) method had the highest correlation, followed by the maceration method. The lowest correlations were found with the pressing method and the blend/water method. CONCLUSIONS Complete homogenisation of tissues with 1:1 or greater ratios of water was necessary for the maximum consistency and full development of the pyruvic acid reaction for onion pungency measurement. © 2015 Society of Chemical Industry