Vegetable preservation by a mixed organic acid fermentation

Lactic acid fermented fruit and vegetables are normally obtained following a natural spontaneous fermentation in which no starter cultures are added. It could be expected that a suitable starter culture would help standardise production. Several lactic acid bacteria were selected for a series of phy...

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Main Author: Delclos, Paul-R. Mrocek
Published: University of Surrey 1991
Subjects:
664
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280339
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spelling ndltd-bl.uk-oai-ethos.bl.uk-2803392018-04-04T03:25:58ZVegetable preservation by a mixed organic acid fermentationDelclos, Paul-R. Mrocek1991Lactic acid fermented fruit and vegetables are normally obtained following a natural spontaneous fermentation in which no starter cultures are added. It could be expected that a suitable starter culture would help standardise production. Several lactic acid bacteria were selected for a series of physiological studies, in a defined medium (MRS broth) and in carrot juices, under varying conditions of growth temperature, salt concentration and carbohydrate source. Based on these, the homofermenter Lactobacillus pentosus and the heterofermenter Leuconostoc mesenteroides were tested as potential starters, in single and mixed cultures, for the fermentation of carrots (Daucus carota), as a novel fermentable substrate, and cabbage (Brassica oleracea) into sauerkraut. Fermentations were performed in the presence of the natural microflora. Sugar catabolism and acid production were monitored through H.P.L.C. In the fermentation of carrots Leuconostoc mesenteroides played a major role, with no homofermenters present. For sauerkraut, the mixed starter culture composed of Leuconostoc mesenteroides and Lactobacillus pentosus gave the closest resemblance to the product normally obtained following a natural commercial fermentation. The inclusion of the heterofermenter provided the required acid balance for correct product flavour and aroma by enhancing production of acetic acid. Acetate is also a better antimicrobial than lactate. A shorter fermentation time was also obtained, reducing the time from 3-4 weeks in the natural fermentation to only 7 days with the use of the mixed starter. When reduced salt concentrations were tried, 1% NaCl (w/w) resembled the spontaneous fermentation more closely, in regard to microbial sequence, pH and total acidity. Different ratios of the two lactic acid bacteria in combination were tried, the best being that in which L, mesenteroides and L. pentosus were initially present in the same proportions. Survival of Listeria monocytogenes in fermenting sauerkraut was shorter when starter cultures were used, but no difference was detectable between mixed and single cultures.664Food technology & food microbiologyUniversity of Surreyhttp://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280339http://epubs.surrey.ac.uk/842740/Electronic Thesis or Dissertation
collection NDLTD
sources NDLTD
topic 664
Food technology & food microbiology
spellingShingle 664
Food technology & food microbiology
Delclos, Paul-R. Mrocek
Vegetable preservation by a mixed organic acid fermentation
description Lactic acid fermented fruit and vegetables are normally obtained following a natural spontaneous fermentation in which no starter cultures are added. It could be expected that a suitable starter culture would help standardise production. Several lactic acid bacteria were selected for a series of physiological studies, in a defined medium (MRS broth) and in carrot juices, under varying conditions of growth temperature, salt concentration and carbohydrate source. Based on these, the homofermenter Lactobacillus pentosus and the heterofermenter Leuconostoc mesenteroides were tested as potential starters, in single and mixed cultures, for the fermentation of carrots (Daucus carota), as a novel fermentable substrate, and cabbage (Brassica oleracea) into sauerkraut. Fermentations were performed in the presence of the natural microflora. Sugar catabolism and acid production were monitored through H.P.L.C. In the fermentation of carrots Leuconostoc mesenteroides played a major role, with no homofermenters present. For sauerkraut, the mixed starter culture composed of Leuconostoc mesenteroides and Lactobacillus pentosus gave the closest resemblance to the product normally obtained following a natural commercial fermentation. The inclusion of the heterofermenter provided the required acid balance for correct product flavour and aroma by enhancing production of acetic acid. Acetate is also a better antimicrobial than lactate. A shorter fermentation time was also obtained, reducing the time from 3-4 weeks in the natural fermentation to only 7 days with the use of the mixed starter. When reduced salt concentrations were tried, 1% NaCl (w/w) resembled the spontaneous fermentation more closely, in regard to microbial sequence, pH and total acidity. Different ratios of the two lactic acid bacteria in combination were tried, the best being that in which L, mesenteroides and L. pentosus were initially present in the same proportions. Survival of Listeria monocytogenes in fermenting sauerkraut was shorter when starter cultures were used, but no difference was detectable between mixed and single cultures.
author Delclos, Paul-R. Mrocek
author_facet Delclos, Paul-R. Mrocek
author_sort Delclos, Paul-R. Mrocek
title Vegetable preservation by a mixed organic acid fermentation
title_short Vegetable preservation by a mixed organic acid fermentation
title_full Vegetable preservation by a mixed organic acid fermentation
title_fullStr Vegetable preservation by a mixed organic acid fermentation
title_full_unstemmed Vegetable preservation by a mixed organic acid fermentation
title_sort vegetable preservation by a mixed organic acid fermentation
publisher University of Surrey
publishDate 1991
url http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280339
work_keys_str_mv AT delclospaulrmrocek vegetablepreservationbyamixedorganicacidfermentation
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