Biochemical Basis of Off-odour Generation in Pearl Millet [Pennisetum glaucum (L.) R. Br.]
KrishiKosh
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Title |
Biochemical Basis of Off-odour Generation in Pearl Millet [Pennisetum glaucum (L.) R. Br.]
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Creator |
Goyal, Preeti
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Contributor |
Chugh, L.K.
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Subject |
flours, millets, enzymes, genotypes, storage, grain, storage structures, acidity, fats, irrigation
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Description |
The present investigation was conducted with the objectives to screen and select contrasting pearl millet genotypes out of 21 including seven hybrids, seven CMS lines, five inbreds and two white composites in respect of off odour generation and to study the effect of grain maturation, growing environment and storage period on chemical/biochemical changes in magnitude of off odour. But development of off odour could not be quantitatively related with either of the parameters [Fat acidity (FA), pH, activity of peroxidase (POX), lipoxigenase (LOX), polyphenol oxidase (PPO), ascorbate peroxidase (APX) and glutathione peroxidise (GPX)]. Nevertheless genotypes were identified based on off odour determinants. Flour of 21 pearl millet genotypes was stored in aluminium boxes at 14 °C and 82% RH. Wide variations in level of biochemical constituents were recorded among the individual genotypes tested. Crude fat content was positively correlated with total phenols with correlation coefficient of 0.451*. The fat acidity in fresh as well as stored flour was negatively correlated with pH of fresh and stored flour with correlation coefficients of -0.477* and -0.578** respectively. Stored samples had decreased activities of POX, LOX and PPO but their activities were higher in fresh flour. Activity of APX and GPX were not detected in flour of any of the genotypes tested. Inbreds G 73-107 and HBL 11 were selected as contrasting genotypes on the basis of fat content, phenolic content, development of fat acidity, changes in pH and activity of POX during storage. To study the effect of maturation grains of two selected genotypes G 73-107 and HBL 11 were harvested at 24, 28 and 32 days after anthesis (DAA) from the field and their flour was analyzed for the same biochemical parameters and data clearly indicated that stages of maturation had no significant effect on the biochemical parameters studied. Selected genotypes were grown under two different environments i.e. irrigated and rainfed condition and grains were used for preparing flour for biochemical analysis. Pattern of increase in fat acidity and decrease in pH was similar under both environmental conditions but slightly higher values were recorded in flour prepared from grains raised under irrigated condition. Non significant differences were observed in activities of POX, LOX and PPO in plants grown under different environments. To find out changes in biochemical parameters responsible for deterioration of flour occur during short term (1, 2, 3, 4 and 5 days) and long term (5, 10, 15, 20, 25 and 30 days) of storage PM and HM flour of the two selected genotypes were stored in aluminium boxes at 37 °C. Rate of increase in FA, decrease in pH and activities of enzymes was rapid up to 10th day of storage and after that it became slow. Thus, biochemical characters investigated were not influenced by environment or maturity of grains and deteriorative changes occurred during early period of storage (within 10 days). Identified inbreds G73-107, HBL 11 may therefore be useful in future breeding programme for developing low rancid pearl millet hybrids/composites. |
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Date |
2016-02-04T12:15:03Z
2016-02-04T12:15:03Z 2015 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/64160
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Language |
en
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Format |
application/pdf
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Publisher |
CCSHAU
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