Juice amino acid composition

Huang, Z. and C.S. Ough. 1989. Effect of vineyard locations, varieties, and rootstocks on the juice amino acid composition of several cultivars. Am. J. Enol. Vitic. 40 135-139. 

The method described above is applicable to a wide range of samples for the determination of amino acids in different matrices. For example, the amino acid composition and distribution of single enantiomers has been determined in protein hydrolysates, orange juice (Fig. 7-11), yogurt and seawater [23]. 

By the use of paper chromotography, an investigation61 of the amino acid composition of the duodenal juice from 10 individuals has revealed that in each case a distinctive and relatively constant amino acid pattern is exhibted. Fifty-six patients62 with various pathological conditions (in gall bladder and liver) were also studied in the same way with similar results. Evidence was found that certain pathologies were associated with specific characteristics of the patterns. 

N Naulet, P Tesson, N Couler, GJ Martin. Optimization of analytical methods for origin assessment of orange juices. II. Determination of the amino acid composition. Analusis 25 42-47, 1997. 

Vandercook et al. (64) developed an automated ninhydrin procedure and measured the absorbance at 480 nm where the molar absorbances of the major orange juice amino acids are nearly equal. Analysis of a series of synthetic amino acid mixtures representing the extremes in amino acid composition (46) resulted in a maximum error of 5%. 

Table II. Amino Acid Composition (mg/lOOml) of Citrus Juices from...

All amino acids, except proline, may be used by Saccharomyces cerevisiae in grape juice fermentation. Amino acids can be directly used to synthesize proteins. However, the amino acid composition of the grape juice is not necessarily similar to the needs of the cell. For that reason, yeasts must use the remaining amino acids to synthesize those which it lacks (Hensche and Jiranek 1993 Ribereau-Gayon et al. 2000b). In this case, ammonia is incorporated into other amino acids whereas the carbon skeleton is metabolized by the cell. 

Finally, the relationship between the amino acid composition of grapes and the final aromatic composition of wine has been recently described (Hernandez-Orte et al. 2002, 2006). Therefore, it is possible that in the near future grape juice will be complemented with specific mixtures of amino acids in order to improve the aromatic quality of wine. 

Spayd, S.E. and j. Andersen-Bagge. 1996. Free amino acid composition of grape juice from 12 Vitis vinifera cultivars in Washington. Am. J. Enol. Vitic. 47 389-402. 

Feline gastrin, a hormone that stimulates secretion of gastric juice in cats, has the amino acid composition (Ala2,Asp,Gly2,GlUj,Leu,Met,Phe,Pro,Trp2,Tyr). 

Water, sugars, organic acids and amino acids make up all tut a few tenths of 1 of "single strength" orange juice. A breakdown of the composition of orange juice is presented in Table I. 

Statistical Analysis The juice composition, as individual amino acids, free amino nitrogen and ratios of certain amino acids and groups of them were entered into a principal component analysis (PCA) using the SAS (Cary, NC) statistical software. The ratios considered were based on the thinking that relative proportions within the amino pool, rather than absolute quantities between alternative substrates might be related to the level of sulfide formation. 

---