In order to improve the health characteristics of buffalo milk and Mozzarella, the effect of two concentrates differing in linoleic acid (LA) content on milk fatty acid (FA) composition was con- sidered. Dietary LA supplementation, in fact, is the most effec- tive strategy to increase milk content of conjugated linoleic acid (CLA), which has potentially positive effects on human health. Thirty-two buffaloes were randomly allotted in two groups: exper- imental (EG) and control (CG). During the first period (P1, from 26 to 82 days in milk) EG fed a total mixed ratio (TMR) composed by barley silage, alfalfa and grass hay, maize meal and 3 kg of a concentrate composed by 30% cracked whole soybean (WS) and 70% horse bean (HB), which provided 12.6 g/kg DM of LA. During the second period, (P2, from 97 to 152 days in milk), the experi- mental concentrate was 70/30 WS/HB that provided 25.4 g/kg DM of LA. During both periods CG fed a diet based on the same for- age than EG and a concentrate composed by maize meal, soybean meal, and cotton seeds (7.2 g/kg DM of LA). Individual milk sam- ples were weekly collected and data of milk FA composition were analysed by a repeated measures model. At the end of each peri- od, milk from each group was separately processed and six Mozzarella cheese for group were sampled. During P1, LA con- tent of milk from EG was significantly higher than milk from CG (1.85 vs. 1.52% of TL), whereas CLA and vaccenic acid (VA) con- tent did not differ between groups. During P2, the LA content in EG milk was more than two times higher than that in CG milk (3.91 vs. 1.59% of TL). Also CLA (0.59% of TL vs. 0.38% of TL for EG and GC respectively) and VA (1.67%of TL vs. 1.25% of TL for EG and CG, respectively) milk content significantly differed between groups. Oleic acid (OA) content significantly differed between treatments, being higher in milk from EG (+17%). Interestingly, differences were observed also in the substrate/product ratio related to stearoil-CoA desaturase enzyme (SCD). This enzyme acts either on C18:0, that is con- verted in OA, and on C14:0, C16:0 and VA, which are converted in cis9 unsaturated FA. Results suggested a higher affinity of SCD for C18:0. The desaturation index of C18:0, in fact, was more than ten times higher than that of other substrates. The FA com- position of mozzarella reflected that observed in milk, confirm- ing that cheesemaking did not affect the transfer of FA from milk to cheese.
|Titolo:||Effect of different doses of cracked whole soybean on milk fatty acid composition in buffalo|
|Anno del prodotto:||2015|
|Appare nelle tipologie:||4.2 Abstract in Atti di convegno|