Accuracy of amino acid analysis of fish meals by ion‐exchange and gas chromatography

Miller, Eric L.; Juritz, June; Barlow, Stuart; Wessels, J. P. H.

doi:10.1002/jsfa.2740470305

Cited by 5 publications

(1 citation statement)

References 21 publications

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“…The fermented fish product has been reported to contain soluble N and Downloaded by [University of Nebraska, Lincoln] at 08:21 05 June 2016 C compounds such as the amino acids histidine, methionine, lysine, serine and tryptophan (Miller et al, 1989;Landry & Delhaye, 1994;Lopetcharat et al, 2001), and organic acids such as lactic acid, acetic acid and formic acid . Similarly, it has been reported that fermented vegetable extracts contain high levels of organic acid or soluble C (Liu, 2003).…”

Section: Discussionmentioning

confidence: 99%

Role of Fermented Bio-extracts Produced by Farmers on Growth, Yield and Nutrient Contents in Cowpea (Vigna unguiculata(L.) Walp.) in Northeast Thailand

Kamla

Limpinuntana

Ruaysoongnern

et al. 2008

Biological Agriculture & Horticulture

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Many small farmers in Northeast Thailand have adopted the on-farm production of fermented bio-extracts as a supplement to, or replacement for, chemical fertilizers. They use bio-extracts either singly or in combination with other organic amendments in crop production. The aim of this study was to investigate the benefit of bio-extract combined with organic fertilizers and alone as a nutrient source for crop biomass and yield. In a pot trial, addition of bio-extract alone at the local farmers' rate and frequency did not increase either biomass or yield of cowpea as its nutrient contents were much lower than those in the chemical fertilizer and all organic fertilizer treatments, and did not supply sufficient amounts of nutrients for crop growth on the low fertility sandy soil. However, in field and pot experiments, addition of bio-extract with organic fertilizers significantly increased plant top dry weight and yield above that obtained with organic fertilizer alone. Animal-based bio-extract gave larger and more consistent yield response than plant-based extract. The lack of response of yield to plant-based bio-extract with organic fertilizer was evident on the higher fertility alluvial soil. It may be concluded that bio-extract enhances the effect of organic fertilizers on cowpea growth. However, it is not clear whether bio-extract enhances crop growth by supplying a significant source of microorganisms or by supplying soluble C and/or N substrate for microbial activity to accelerate decomposition rate of organic fertilizers and release nutrients for the crop production.

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Section: Discussionmentioning

confidence: 99%

Role of Fermented Bio-extracts Produced by Farmers on Growth, Yield and Nutrient Contents in Cowpea (Vigna unguiculata(L.) Walp.) in Northeast Thailand

Kamla

Limpinuntana

Ruaysoongnern

et al. 2008

Biological Agriculture & Horticulture

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Accuracy and precision in amino acid analysis

Davies¹,

Baigent

Levitt

et al. 1992

J Sci Food Agric

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Five laboratories collaborated in a two-part study to improve and measure the accuracy and precision of amino acid analysis. The results of the unpublished first part allowed each laboratory the opportunity to optimise their own procedure. In the second part of the study reported here, three purified and six conventional proteins were analysed, each after three different preparation procedures (normal and extended acid hydrolysis, and following preliminary oxidation). Preparative effects reported in the literature were confirmed though not uniformly, and there were other, often unique, preparative effects. Well documented preparative effects are essential in matching analytical work to differing requirements. Results from one laboratory were excluded from further statistical analysis because of high replicate variation. The repeatability (within laboratory) coefficient of variation was 4.1 YO and for reproducibility (between laboratory) it was 13.1 YO. Discrepancies between best amino acid estimates for purified proteins and estimates calculated from published sequences (P < 0.01) provided evidence of bias in five amino acids from one laboratory and in one from another. When P < 0.01 was used as the discard threshold for conventional protein results, a total of 9.9% of best estimates were discarded: 8-1 "LO were biased, 3.2 % were outliers and 1.3 % were both biased and outliers. When these values were discarded, 19 of 96 mean values changed by up to 4%, nine changed by 4-8 YO, eight changed by larger amounts and the pooled coefficient of variation fell from 8.2% to 5.4%. At this threshold between zero and 31 YO of each laboratory's data on conventional proteins was discarded. A lower threshold (P < 0.05) doubled the discard rate but had marginal effects on mean values and residual variation. At P c 0.01 less than 20% of biased estimates were also outliers and less than half the outliers were also biased. This means that only studies which examine both accuracy and precision will achieve maximum improvement in either.

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Nitrogenous Compounds

Pomeranz¹,

Meloan²

1994

Food Analysis

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Accuracy of amino acid analysis of fish meals by ion‐exchange and gas chromatography

Abstract: A B S T R A C T Variations in amino acid content of fish meals can he due to dijjerences bet ween meals or to analytical shortcomings. The purpose of the cooperatitie study reported here was to compare the accuracy of the ion-exchange ( I E )and gas chromatographic (GC)

Cited by 5 publications

References 21 publications

Role of Fermented Bio-extracts Produced by Farmers on Growth, Yield and Nutrient Contents in Cowpea (Vigna unguiculata(L.) Walp.) in Northeast Thailand

Role of Fermented Bio-extracts Produced by Farmers on Growth, Yield and Nutrient Contents in Cowpea (Vigna unguiculata(L.) Walp.) in Northeast Thailand

Accuracy and precision in amino acid analysis

Nitrogenous Compounds

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