RESUMEN
Ice cream samples were made with a mix composition of 11% milk fat, 11% milk solids-not-fat, 13% sucrose, 3% corn syrup solids (36 dextrose equivalent), 0.28% stabilizer blend, or 0.10% emulsifier and vanilla extract. Mixes were high temperature short time pasteurized at 80 degrees C for 25 s, homogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second, and cooled to 3 degrees C. The study included six treatments from four batches of mix. Mix from batch one contained 0.10% emulsifier. Half of this batch (treatment 1), was subsequently frozen and the other half (upon exiting the pasteurizer) was reheated to 60 degrees C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (treatment 2), and cooled to 3 degrees C. Mix from batch two contained 0.28% stabilizer blend. Half of this batch was used as the control (treatment 3), the other half upon exiting the pasteurizer was reheated to 60 degrees C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (treatment 4), and cooled to 3 degrees C. Batch three, containing 0.10% emulsifier and 1% whey protein concentrate substituted for 1% nonfat dry milk, upon exiting the pasteurizer was reheated to 60 degrees C, rehomogenized at 141 kg/cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (treatment 5), and cooled to 3 degrees C. Batch four, containing 0.28% stabilizer blend and 1% whey protein concentrate substituted for 1% nonfat dry milk, upon exiting the pasteurizer was reheated to 60 degrees C, rehomogenized at 141 kg/ cm2 pressure on the first stage and 35 kg/cm2 pressure on the second (treatment 6), and cooled to 3 degrees C. Consistency was measured by flow time through a pipette. Flow time of treatment 3 was greater than all treatments, and the flow times of treatments 4 and 6 were greater than treatments 1, 2, and 5. Flow time was increased in ice cream mix by the addition of stabilizer. Double homogenization lowered ice cream mix flow time in the presence of stabilizer, but no difference in flow time was observed without stabilizer addition. Treatment 4 had a lower mean ice crystal size at 10 d postmanufacture compared with treatment 3; however, overall texture acceptability between treatments 3 and 4 was similar. Mean ice crystal size of treatment 6 was less at 18 wk postmanufacture compared with treatment 3; however, overall texture acceptability for treatments 3, 4, and 6 was similar. Mean ice crystal sizes of treatments 1, 2, and 5 were greater at 10 d and 18 wk compared with treatment 3. Sensory evaluation indicated that treatments 3, 4, and 6 had higher mean scores for icy, coldness intensity, and creaminess than treatments 1, 2, and 5 at 10 d and 18 wk postmanufacture.
Asunto(s)
Manipulación de Alimentos/métodos , Tecnología de Alimentos , Helados/normas , Proteínas de la Leche/química , Animales , Emulsiones , Helados/análisis , Tamaño de la Partícula , Presión , Reología , Temperatura , Proteína de Suero de LecheRESUMEN
Eight multiparous Holstein and four multiparous Brown Swiss (78 +/- 43 DIM) cows were used in a 4 x 4 Latin square with 28-d periods to evaluate if feeding fish oil with a source of linoleic acid (extruded soybeans) would stimulate additional amounts of conjugated linoleic acid in milk. Four treatments consisted of a control diet with a 50:50 ratio of forage to concentrate (DM basis), a control diet with 2% added fat from either menhaden fish oil or extruded soybeans, or a combination of fish oil and extruded soybeans each adding 1% fat. DM intake (24.3, 21.6, 24.5, and 22.5 kg/d, for control, fish oil, extruded soybeans, and combination diets, respectively), milk production (32.1, 29.1,34.6, and 31.1 kg/d), and milk fat content (3.51, 2.79, 3.27, and 3.14%) were lower for cows that consumed either fish oil-containing diet, especially the 2% fish oil diet. The proportion of n-3 fatty acids in milk fat increased similarly among all three fat-supplemented diets. Concentrations of transvaccenic acid (1.00, 4.16, 2.17, and 3.51 g/100 g of fatty acids) and cis-9, trans-11 conjugated linoleic acid (0.60, 2.03, 1.16, and 1.82 g/100 g of fatty acids) in milk fat increased more with fish oil than with extruded soybeans. When fed the combination diet, these fatty acids were approximately 50% higher than expected for Holsteins, whereas concentrations were similar for Brown Swiss compared with feeding each fat source separately. These data indicated that fish oil modifies ruminal or systemic functions, stimulating increased conversion of linoleic acid into transvaccenic and conjugated linoleic acids.
Asunto(s)
Bovinos/metabolismo , Aceites de Pescado/administración & dosificación , Ácido Linoleico/análisis , Lípidos/análisis , Leche/química , Alimentación Animal , Animales , Bovinos/fisiología , Ácidos Grasos/análisis , Ácidos Grasos Omega-3/administración & dosificación , Femenino , Ácido Linoleico/administración & dosificación , Glycine max/químicaRESUMEN
Milk was collected from eight multiparous Holstein and four multiparous Brown Swiss cows that were distributed into four groups and arranged in a randomized complete block design with four 4-wk periods. The four treatments included a control diet of a 50:50 ratio of forage-to-concentrate; a fish oil diet of the control diet with 2% (on dry matter basis) added fat from menhaden fish oil; a fish oil with extruded soybean diet of the control diet with 1% (on dry matter basis) added fat from menhaden fish oil and 1% (on dry matter basis) added fat from extruded soybeans; and an extruded soybean diet of the control diet with 2% (on dry matter basis) added fat from extruded soybeans. Milk from cows fed control, fish oil, fish oil with extruded soybean, and extruded soybean diets contained 3.31, 2.58, 2.94, and 3.47% fat, respectively. Concentrations of conjugated linoleic acid in milk were highest in the fish oil (2.30 g/100 g of fatty acids) and fish oil with extruded soybean (2.17 g/100 g of fatty acids) diets compared with the control (0.56 g/100 g fatty acids) diet. Milk, cream, butter, and buttermilk from the fish oil, fish oil with extruded soybean, and extruded soybean diets had higher concentrations of transvaccenic acid and unsaturated fatty acids compared with the controls. Butter made from the extruded soybean diet was softest compared with all treatments. An experienced sensory panel found no flavor differences in milks or butters.
Asunto(s)
Mantequilla/análisis , Bovinos/fisiología , Aceites de Pescado/administración & dosificación , Glycine max , Leche/química , Alimentación Animal , Animales , Bovinos/metabolismo , Grasas/análisis , Ácidos Grasos Insaturados/análisis , Femenino , Ácido Linoleico/análisis , Distribución Aleatoria , GustoRESUMEN
A consumer evaluation was undertaken to determine whether there were differences in the acceptability of milk from cows fed a control or a fish oil diet. The two treatments included a control diet of a 50:50 ratio of forage-to-concentrate and fish oil added to the control diet with 2% (on dry matter basis) added fat from menhaden fish oil. Milk from cows fed the control or fish oil diet contained 3.31 and 2.58% fat and 0.56 and 2.30 g of total conjugated linoleic acid/100 g of fatty acids, respectively. Consumer evaluation of control and fish oil milks found no difference in acceptability.
Asunto(s)
Comportamiento del Consumidor , Aceites de Pescado/administración & dosificación , Ácido Linoleico/análisis , Leche/química , Adulto , Alimentación Animal , Animales , Bovinos , Dieta/veterinaria , Femenino , Humanos , Masculino , Encuestas y Cuestionarios , GustoRESUMEN
A control diet and a fish oil diet were fed to 12 multiparous Holstein cows to determine how the incorporation of Menhaden fish oil in the diet would influence the fatty acid composition, especially the conjugated linoleic acid and transvaccenic acid, contents of milk and butter. The control diet consisted of a 50:50 ratio of forage to concentrate, and the fish oil diet consisted of the control diet with 2% (on a dry matter basis) added fish oil. Milk from cows fed the control diet contained higher average concentrations of milk fat (3.37%) compared with milk from cows fed the fish oil diet (2.29%). Milk from cows fed fish oil contained higher concentrations of conjugated linoleic acid, transvaccenic acid, and total unsaturated fatty acids (0.68 and 2.51; 1.42 and 6.28; and 30.47 and 41.71 g/100 g of fat, respectively). Butter made from the fish oil diet milk also had higher concentrations of conjugated linoleic acid, transvaccenic acid, and unsaturated fatty acids. Penetrometer readings indicated fish oil diet butters were softer at 4 and 20 degrees C than the control diet butters. Acid degree values were similar in the fish oil butters compared with the control butters. No significant difference was found in the flavor characteristics of milk and butter from cows fed the control and fish oil diets. Production of milk and butter with increased amounts of conjugated linoleic acid, transvaccenic acid, and other beneficial fatty acids may have a desirable impact on the health of consumers and lead to increased sales.
Asunto(s)
Mantequilla , Grasas Insaturadas en la Dieta/farmacología , Ácidos Grasos/análisis , Aceites de Pescado/farmacología , Leche/química , Animales , Bovinos , Fenómenos Químicos , Química Física , Dieta , Grasas Insaturadas en la Dieta/administración & dosificación , Ácidos Grasos/química , Femenino , Aceites de Pescado/administración & dosificación , Lactancia , Ácido Linoleico/análisis , Leche/metabolismo , GustoRESUMEN
Cream was homogenized in a two-stage homogenizer (17.25 MPa in the first stage and 3.43 MPa in the second stage); blended with skim milk to produce milk containing 1.25% fat, which was pasteurized (63 degrees C for 30 min); and then manufactured into reduced fat Cheddar cheese. After milling, the curd was divided into three equal portions of 13 kg each. Three salting rates, 2.3, 3.8, and 5%, yielded cheeses with 1.3, 1.7, and 2.0% salt and 2.7, 3.7, and 4.5% salt in the moisture phase. Cheese moisture contents ranged from 45% (2.0% salt) to 47.7% (1.3% salt), and fat contents ranged from 14.6 to 15.1%. In the texture profile analysis, the hardness and fracturability of the cheeses increased as the salt content increased. Both parameters decreased during ripening, but cheeses with 4.5% salt in the moisture phase remained the hardest. Cheeses with the most salt had the least desirable body characteristics, but there were no differences in flavor. Intensity of bitterness was lowered as the amount of salt in cheese increased. During ripening, the number of lactic acid bacteria decreased more slowly in cheese with 2.7% salt in the moisture phase than in those with 3.7 or 4.5% salt in the moisture phase. As the salt content increased, proteolysis and the general rate of ripening decreased. Degradation of alpha s-casein was reduced by higher percentages of salt, but no differences were found in the degradation of beta-casein.
Asunto(s)
Queso/análisis , Grasas de la Dieta/análisis , Tecnología de Alimentos , Cloruro de Sodio/farmacología , Bacterias/crecimiento & desarrollo , Caseínas/análisis , Caseínas/química , Queso/microbiología , Electroforesis en Gel de Poliacrilamida , Endopeptidasas/metabolismo , Ácido Láctico/metabolismo , Sensación , GustoRESUMEN
A control diet and three experimental diets were fed to midlactation Holstein cows to evaluate the effects of dietary unsaturated fatty acids and niacin on milk and reduced fat Cheddar cheese. The diet consisted mainly of rolled corn and soybean meal in the concentrate mixture. Experimental diets consisted of the control diet with added niacin and the control diet but with extruded soybeans substituted for part of the corn and soybean meal, with and without added niacin. Milks from cows fed diets of extruded soybean and extruded soybeans with added niacin contained lower concentrations of short- and medium-chain fatty acids and higher concentrations of long-chain fatty acids. Cheese milks consisted of a control, a homogenized control (3.45 MPa), and unhomogenized and homogenized milks (3.45 MPa) from cows fed extruded soybeans with added niacin. Reduced fat Cheddar cheeses produced from unhomogenized and homogenized milks from the cows fed extruded soybeans with added niacin contained higher concentrations of unsaturated fatty acids. The reduced fat Cheddar cheeses maintained acceptable flavor, body, and texture during storage. Homogenization of cheese milk had little effect on cheese properties. Cheeses manufactured from milks with high amounts of unsaturated fatty acids were softer; however, this difference was not detected by the sensory panel.