Effects of Supplementing Grape Pomace to Broilers Fed Polyunsaturated Fatty Acids Enriched Diets on Meat Quality

Simple Summary

Chicken meat and its products are among the first-choice foods in most countries, due to the health benefits they provide and the relatively low price. However, polyunsaturated fatty acids (PUFA) are highly susceptible to peroxidation, affecting nutritional, sensory characteristics and meat shelf life. A reasonable way and a good tactic to delay their lipid peroxidation would be using a natural antioxidant in feed formulation. Grape pomace (GP) is an agro-industrial by-product with high nutritional value as it is a rich source of polyphenols. The supplementation of broiler diets with grape pomace indicated an intensified color, improved texture and a decrease of lipid peroxidation parameters of broilers’ meat that had been fed with PUFA enriched diets.

Abstract

The effects of using grape pomace as natural antioxidant in polyunsaturated fatty acids enriched broiler diets (4% flaxseed meal) on color, texture and lipid peroxidation of meat were evaluated. The 4-week feeding trial was conducted on 200, Cobb 500 broilers, assigned to 5 groups and housed in an experimental hall with floored pens. Compared to the control group, the diet for the experimental groups included 3% or 6% of two grape pomace varieties, white and red. Diet formulation enrichment with red grape pomace influenced the meat color parameters, underlining an accentuated total color difference (ΔE) for both breast and thigh as compared to the control. The dietary supplementation with grape pomace led to the increase of meat hardness regardless of the amount and variety added. The grape pomace inclusion in broiler diets positively influenced meat color and texture. Regarding the lipid oxidation parameters, there was a decrease of the value of thiobarbituric acid-reactive substances (TBARS) in thigh meat in all experimental groups. Additionally, significant differences were highlighted for breast in 3% white grape pomace and 6% red grape pomace supplemented groups when compared to the control group. In conclusion, the supplementation of broiler diets enriched in PUFA with grape pomace improved meat color and texture, which are essential parameters for consumer’s choice. Also, the grape pomace supplementation indicated an improvement of thigh meat oxidative stability, especially regarding the TBARS value.

Comparison and relationship between meat colour and antioxidant capacity of different pig breeds

The objectives of this study were to evaluate meat colour, antioxidant performance of longissimus muscle in different pig breeds, including five Chinese native pig breeds, a Chinese bred pig breed as well as a commercial crossbred pig breed, and to analyse the relationships between meat colour and antioxidant capacity. The results showed that the Chinese native and bred pig breeds have higher meat colour and marbling scores than commercial crossbred pigs. The Chinese native and bred pig breeds showed significantly stronger total antioxidant capacity and superoxide dismutase activity, and lower malondialdehyde contents than commercial crossbred pigs. Moreover, the total antioxidant capacity, superoxide dismutase activity were positively correlated with visual colour, a* and chroma, and negatively correlated with L* and hue angle; on the contrary, the malondialdehyde content was negatively correlated with visual colour, marbling, a*, b* and chroma, and positively correlated with L* and hue angle. In addition, principal component 1 and 2 explained 46.41% and 18.30% of the total variance. These results indicated that meat colour and antioxidant capacity were affected by pig breeds, and meat colour was strongly correlated with antioxidant capacity.

Effects of grape pomace in growing lamb diets compared with vitamin E and grape seed extract on meat shelf life

The effect of dietary treatment (CTRL, control; VIT-E, 500 mg kg(-1) vitamin E; GSE, 50 mg grape seed extract kg(-1); GP-5, 5% dried red grape pomace kg(-1)) on shelf life of lamb meat was studied. After slaughter (27 kg LBW), m. longissimus thoracis et lumborum was sliced, packaged under modified atmosphere (80:20%/O2:CO2) and stored in retail conditions for 14 days. At each sampling day (0, 4, 7, 11, 14), microbiological, physico-chemical and sensory characteristics were analysed. Meat from VIT-E presented lower microbial counts than CTRL, GSE and GP-5, without differences between polyphenol treatments (GSE and GP-5) and CTRL. Vitamin E reduced meat discoloration and lipid oxidation (TBARS values) from day 7 with respect to the other treatments. Although not significant, an improvement in TBARS values of about 20% was observed for GSE and GP-5, compared with CTRL, from day 7 of storage. VIT-E dietary treatment was more effective in preventing sensory spoilage than the other treatments.

Chemical composition, fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves, sunflower cake and grass hay

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62±0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51±0.19% (93.51±0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95±0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (P<0.05) higher than other meat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability).