Effects of Nutritional Factors on Fat Content, Fatty Acid Composition, and Sensorial Properties of Meat and Milk from Domesticated Ruminants: An Overview.

The meat and milk products from domesticated ruminants are important foods within a balanced diet, offering a rich source of energy, protein, fats, minerals, and vitamins. The sensorial properties of meat and milk are mainly linked to their fat content and fatty acid composition, which are influenced by the feeding background or nutrient composition of diets. While several studies have investigated the nutritional effects on the fat content and fatty acid profile of ruminant meat and milk, as well as their relationship with sensorial properties, a comprehensive overview of these effects is lacking. This paper summarises current literature and discusses changes to fatty acid composition (including ω-3 concentrations), fattiness, and associated quality traits of sheep, goat, beef cattle, alpaca, and llama meat that can be achieved by using different forages or feeds in a total mixed ration. Additionally, it presents the shelf life and nutritional value of meat, milk, and cheeses from the milk of dairy cattle, buffalo, goats, and sheep as influenced by a ruminant diet. Further advancement in these areas will promote the sustainability of ruminant production and its associated feeding systems in achieving premium quality animal-derived foods.

Harnessing the untapped potential of indigenous cow milk in producing set-type yoghurts: case of Thamankaduwa White and Lankan cattle.

This research paper assessed textural, microstructural, sensory and colour properties of set-yoghurts produced using milk from two indigenous cattle types, Thamankaduwa White (TW) and Lankan cattle (LC) compared to two generic cattle breeds, Friesian and Jersey. Instrumental texture profile (firmness, adhesiveness, cohesiveness and springiness), colour space (L* a* b*) and scanning electron micrographs of set-yoghurts during 21 d of storage (4 ± 1°C) were evaluated. Sensory quality attributes were evaluated with 40 untrained panellists using a five-point hedonic scale. Set-yoghurts prepared using indigenous cow milk showed higher (P < 0.05) firmness, cohesiveness and apparent viscosity values compared to those prepared using generic cow milk. As revealed by micrographs, set-yoghurts made from TW milk had lesser and smaller void spaces and a dense protein gel network than gels made from LC and the two generic breeds. The gel network made from Friesian milk showed a comparatively larger porous gel structure and thinner protein strands resulting in a weaker gel than other milk gels. The highest lightness (L*) and yellowness (b*) were observed from set-yoghurt produced from Friesian and LC milk, respectively. Set-yoghurts from TW milk had the highest (P < 0.05) sensory scores for all sensory attributes. The lowest sensory acceptance was recorded in set-yoghurt made from Friesian milk. Thus, milk from TW and LC is likely to be suitable in producing set-yoghurts with superior textural, microstructural and sensory properties, compared to milk from Jersey and Friesian. Our results suggest the merits of using indigenous cow milk in producing set-yoghurts and, thereby, prioritizing the preservation of the genetic pool of these indigenous breeds.

Algae-based antioxidant containing selenium yeast (Economase®) enhanced the growth performance, oxidative stability, and meat quality of broiler chickens.

OBJECTIVE: An experiment was conducted to determine the effect of algae-based antioxidant containing Se yeast (EconomasE®) on the growth performance, visceral organ weight, meat quality, and oxidative stability of broiler chickens. METHODS: Nine hundred sixty, day-old male broiler chickens (Cobb, 43.97±0.55 g) were divided into three dietary treatments and allocated into 12 deep litter pens in a completely randomized design giving 4 replicate cages for each treatment. Three dietary treatments were: i) control (CON, basal diet with sufficient nutrient), ii) vitamin E (VitE, basal diet supplemented with 100 IU VitE), and iii) Algae-based antioxidant containing Se yeast (EcoE, basal diet supplemented with 0.2% algae-based antioxidant containing Se yeast: EconomasE®). Maize soybean meal based basal diets were formulated to meet or exceed the nutrition requirement for broiler chickens. Chickens were fed ad-libitum experimental diets during the 42 days experiment period. On days 21 and 42, body weight and feed intake were measured to calculate the feed conversion ratio of the chickens. Intestine and visceral organs were measured together with meat quality and oxidative stability on days 14 and 42. RESULTS: Chickens fed with EcoE showed improved (p<0.05) growth performance, meat quality, and higher (p<0.05) oxidative stability compared to the chicken fed on CON. Moreover, broiler chickens fed with EcoE showed similar (p<0.05) growth performance with better (p<0.05) meat quality and higher oxidative stability compared to the broiler chickens fed VitE (p<0.05). CONCLUSION: The algae-based antioxidant containing Se yeast can be supplemented into commercial broiler diets as a substitution of VitE while maintaining growth performance with enhancing meat quality and oxidative stability of the broiler chickens.

The physicochemical, microbiological, and organoleptic properties and antioxidant activities of cream cheeses fortified with dried curry leaves (Murraya koenigii L.) powder.

We aimed to investigate the effects of dried curry leaves powder (CLP) incorporation on physicochemical, microbiological, antioxidant, and sensory properties of cream cheeses. Varying levels of CLP infusions (i.e., T1: 0% [control], T2: 0.15%, T3: 0.2%, and T4: 0.25%; w/w%) were stored for 10 days at 4°C. Antioxidant properties were evaluated using total phenolic content, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging ability, and ferric reducing antioxidant power using in vitro assays. Total antioxidant capacity significantly (p < .05) increased with the increasing levels of CLP. Physicochemical and microbiological qualities were not significantly affected by the addition of CLP, indicating the suitability of using CLP without compromising the quality of cream cheese. Organoleptic properties were affected with CLP addition, where T3 had the highest scores for color, aroma, flavor, texture, and overall acceptability. The principal component analysis provides the holistic approach of studying the variation associated with cream cheeses and the overall relationship among studied parameters. This provides strong references for novel dairy products added with antioxidant-rich Murraya koenigii L. powder. The study also has merits to promote scientific knowledge concerning, and how the incorporation would influence the physicochemical, organoleptic, and microbiological properties of cream cheese to deliver the value-added or diversified product to emerging consumers.

Type of starter culture influences on structural and sensorial properties of low protein fermented gels.

Organoleptic properties of skimmed milk fermented gels are progressively demanding to produce optimal quality yogurts. Chr-Hansen trademark registered cultures were used to produce low-protein (3.4%) gels to assess the ability to redesign the sensorial and textural properties with the choice of starter culture. Resulting gels were assessed for sensorial, textural, rheological, and microstructural properties and compared with a commercial control (4.5% protein). Mouth thickness, syneresis, firmness, elasticity, and consistency values were lower for polysaccharides-producing cultures. Such cultures contributed to the higher creaminess and tended to give higher ropiness. Observed differences among microstructures of the gel were minute. Microstructural and rheological data corresponded and reflected the instrumental and sensory interpretations. Strong correlations were observed between sensory and instrumental data. Nonprobiotics cultures resulted in promising overall gel properties compared with probiotic cultures according to the principal component analysis. Yet probiotic cultures resulted in lower syneresis than nonprobiotic cultures. Thus, the choice of bacterial culture modifies the sensorial and textural properties of fermented gel with strong correlations, as a result of altered gel network formation with the production of polysaccharides. Inferior textural and sensorial quality aspects, particularly at low protein levels, have negative impact on consumer demand of low protein yogurts. Thus, we attempted to gain required gel textural and sensorial properties with a choice of starter culture with a low protein level. Resulting gel properties at lowered protein content with different starter cultures are not fully known. The present study compares the effect of probiotic and nonprobiotic starter cultures on gel properties, as gel texture and sensory properties are of great interest and thus not willing to be compromised. In addition, we examined the overall texture profile of studied cultures and correlate with sensory properties. Therefore, reducing protein level in milk and achieving required gel properties with the choice of appropriate starter culture is of great commercial interest as a cost-cutting strategy to produce low-cost optimum quality yogurt.

Boiled, sprouted, and raw cowpea-incorporated diets modulate high-fat diet-induced hypercholesterolemia in rats.

This study was carried out to investigate the effect of processed (boiled and sprouted) cowpea-incorporated experimental diets on serum cholesterol and serum antioxidant capacity in high-fat diet (HFD)-fed Wistar rats. Seven weeks old male Wistar rats were fed 20% fat as a control (CD), for comparison with 20% fat-enriched diets containing 20% whole raw cowpea diets (Bombay Raw Diet; BRD and MI35 Raw Diet; MRD), boiled cowpea diets (Bombay Boiled Diet; BBD and MI35 Boiled Diet; MBD) and sprouted cowpea diet (Bombay Sprouted Diet; BSD) for 6 weeks. The increase in serum total cholesterol as a result of high-fat diet was significantly countered by boiled and raw cowpea-incorporated diet-fed rats. Increased serum non-HDL-C level caused by HFD was significantly (p < 0.05) countered by raw, boiled, and sprouted cowpeas, while HDL-C was increased by raw MI and boiled Bombay incorporated diets. Boiling has improved the hypocholesterolemic ability of Bombay cowpea and BBD has significantly (p < 0.05) modulated serum HDL-C level and liver weight in rats. These findings were supported significantly high soluble fiber content in processed cowpea powder than that in raw cowpea powder. The decrease in serum antioxidant activity as a result of HFD was significantly countered by BRD. Processing has reduced the antioxidant activity in cowpeas and serum antioxidant activity in rats. Cecal lactobacilli population was significantly high in all cowpea diet-fed groups compared to control. Modulated serum cholesterol level in cowpea diet-fed rats was accompanied by dietary fiber composition, antioxidant activity in cowpeas and fecal weight, cecal weight and cecal lactobacilli population in rats compared to control. Both processed and raw cowpea-incorporated diets have modulated HFD-induced hypercholesterolemia by modulating serum antioxidative capacity, cholesterol metabolism, and cecal fermentation.

Banana Blossom (Musa acuminate Colla) Incorporated Experimental Diets Modulate Serum Cholesterol and Serum Glucose Level in Wistar Rats Fed with Cholesterol.

Hypocholesterolaemic and hypoglycaemic effect of banana blossom were studied in high-cholesterol fed rats. Experimental groups were fed for 4 weeks, with casein as the basal diet (CN), in comparison with two diets containing 0.5% cholesterol (CD) and 0.5% cholesterol + 21% banana blossom powder (CDB). Serum total cholesterol, non-HDL-cholesterol level, and serum glucose concentrations were lower in CDB fed group compared with CD fed group. Lower serum cholesterol and glucose level (P < 0.05) in CDB fed group were followed by higher faecal weight, caecal weight, caecal Lactobacilli, and Bifidobacteria population in CDB fed group compared to CD diet fed group. Lower serum AST level in banana blossom fed rats showed the reduction in oxidative stress induced by high cholesterol diet. Based on these data, it could be speculated that banana blossom incorporated experimental diets may modulate the hypocholesterolaemic and hypoglycaemic responses in Wistar rats.

Short communication: Lipolytic activity on milk fat by Staphylococcus aureus and Streptococcus agalactiae strains commonly isolated in Swedish dairy herds.

The objective of this study was to determine the lipolytic activity on milk fat of 2 bovine mastitis pathogens, that is, Staphylococcus aureus and Streptococcus agalactiae. The lipolytic activity was determined by 2 different techniques, that is, thin-layer chromatography and an extraction-titration method, in an experimental model using the most commonly occurring field strains of the 2 mastitic bacteria isolated from Swedish dairy farms. The microorganisms were inoculated into bacteria-free control milk and incubated at 37°C to reflect physiological temperatures in the mammary gland. Levels of free fatty acids (FFA) were analyzed at time of inoculation (t=0) and after 2 and 6h of incubation, showing significant increase in FFA levels. After 2h the FFA content had increased by approximately 40% in milk samples inoculated with Staph. aureus and Strep. agalactiae, and at 6h the pathogens had increased FFA levels by 47% compared with the bacteria-free control milk. Changes in lipid composition compared with the bacteria-free control were investigated at 2 and 6h of incubation. Diacylglycerols, triacylglycerols, and phospholipids increased significantly after 6h incubation with the mastitis bacteria, whereas cholesterol and sterol esters decreased. Our results suggest that during mammary infections with Staph. aureus and Strep. agalactiae, the action of lipases originating from the mastitis pathogens will contribute significantly to milk fat lipolysis and thus to raw milk deterioration.

Applications of marine nutraceuticals in dairy products.

The concept of nutraceutical has been derived by coining the terms "nutrition" and "pharmaceutical". In this context, active substances with pharmaceutical properties are delivered to the humans through food-based approaches to prevent or treat certain disease conditions. Since the natural sources are recognized as safe for human consumption, the active substances produced in the diverse group of marine organisms have a wide role in the nutraceutical industry. These marine-derived active ingredients include certain polysaccharides, polyphenols, bioactive peptides, polyunsaturated fatty acids, and carotenoids which are known to have anticancer, anti-inflammatory, antioxidant, antiobese, hypocholesteroleic, antimicrobial, prebiotic, and probiotic activity enabling them to be applied as nutraceuticals. As the dairy products are widely accepted by the consumers, the delivering of nutraceuticals through dairy products have received a greater attention of the dairy industry. Since the incorporation of marine-derived active ingredients into the dairy products have caused minimal changes in the physico-chemical properties of the final product, marine-derived substances have been widely applied and have the potential to be applied as nutraceuticals in the dairy industry.