A Study On Minor Proteins In Buffalo Milk And Their Nutritional Quality
Abstract: Milk contains in addition to its major components some minor proteins, which play important roles and functions. Most of these components in order escape in the milk by-products after traditional milk processing, i.e. whey or butter-milk. The aim of present investigation was to evaluate two of buffalo minor milk proteins, namely lactoferrin (LF) and milk fat globule membrane protein (MFGMP). Such evaluation is essential for encouraging the utilization of these components in order to increase the economical return of milk processing.
The changes in LF content of colostrum and milk of buffalo during the first four weeks post parturition were investigated.
Individual colostrum or milk samples were taken through the first month of lactation representing colostrum (1st – 3rd day), transitional (4th–7th day) and mature milk (14th–28th day) periods. The samples were analysed for LF content and some related properties.
The LF content of colostrum as determined by ion exchange chromatography was significantly higher than those of transitional or mature milk periods; averages were 591.67, 225.0 and 152.5 mg/L, respectively. Electrical conductively, total solids and total protein content took positive trend as LF contents between different periods. The variations in LF content during the different periods of the first month of lactation due to individuality were insignificant.
The polyacrylamid gel electrophoresis examination showed that colostrum LF bands almost appeared at the same distance as the standard band, but with less density. By advancing in the lactation period the LF bands gradually become more faint.
The iron content of LF averaged 0.15 mg/g LF in colostrum, gradually increased to 0.48 mg in transitional period and reaching its highest average being 1.44 mg in mature milk period. As a result, the LF iron saturation showed its lowest percentage in colostrum, average being 11% only, while its highest level was in mature milk being 103%.
Colostrum LF showed higher content of Asp, Pro, Cys, Val and Arg amino acids than those of transitional or mature milk. However, the most abundant two amino acids in buffalo LF were Glu and Asp in the three investigated lactation periods.
The second minor milk protein concerned in the present research was the MFGMP which was separated from combined buffalo butter-milk and butter serum by isoelectric precipitation at pH 4.0. The average content of MFGMP amounted to 0.42% of milk fat content which equals 30.1% of MFGM material.
The electrophoretic analysis of MFGM protein showed eleven components; four of these polypeptides has Mol. wt. in the range of 24 -96 KDa, while the remaining seven components were extrapolated with Mol. wt. ranged between 109.11 – 0.76 KDa.
The MFGMP showed higher content of Glu, Asp, Ser, Gly, Ala, Isl and Arg amino acids, while Thr, Val, Leu, Pha, Tyr, His and Lys amino acids gave lower levels.
Publication year 2005
Availability location المركز الإقليمي للأغذية والأعلاف - ش جامعه القاهرة - الجيزة
Availability number
Organization Name
Country Egypt
Author(s) from ARC
Proposed Agrovoc البروتينات في اللبن الجاموسى;
Publication Type Master Thesis
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