Effect of canola oil emulsion injection on processing characteristics and consumer acceptability of three muscles from mature beef.

The study was undertaken to investigate the impact of the combined effect of blade tenderization and canola oil emulsion injection on processing yield and eating quality-related parameters of selected loin and hip muscles (longissimus lumborum, LL, biceps femoris, BF and semimembranosus, SM) from over thirty month (OTM) cattle. Canola oil emulsion injection significantly reduced shear force, increased sensory scores for juiciness and tenderness, and made connective tissue less perceptible. Targeted levels of omega-3 fatty acids can be achieved by the inclusion of canola oil containing marinades/emulsions at levels sufficient to retain omega-3 fatty acids in cooked product. All consumer acceptability attributes of OTM muscles were improved with the use of canola oil emulsion injection treatments without compromising colour although slightly decreasing oxidative stability of BF muscle. Injection of omega-3 oil emulsions in combination with blade tenderization can be effectively utilized to enrich injected products in essential fatty acids and enhance eating quality of OTM beef.

Chemical composition characteristics of the longissimus and semimembranosus muscles for pigs from New Zealand and Singapore.

A range of composition characteristics of the longissimus (LL) and semimembranosus (SM) muscles were compared between pigs raised in intensive and extensive production systems in New Zealand (NZ), and pigs raised in an intensive system in Indonesia for supply to the Singapore market (n=8/group). Ultimate pH was slightly higher for the Singaporean LL muscles (P<0.05), while LL muscle of the NZ extensive group was redder (higher a(∗) values) and contained more fat (P<0.05). Muscle iron levels were highest for the NZ extensive group and lowest for a lighter group within the Singapore pigs (P<0.05). Differences in fatty acid concentrations, which were also measured in a sample of the belly cut, could largely be attributed to the effects of diet, with higher levels of alpha linolenic acid for the NZ extensive group (P<0.05) due to linseed in the diet, and much higher levels of linoleic acid and the P:S ratio for the Singapore group (P<0.05). Some statistically significant differences in amino acid concentrations were shown between muscles and groups, but they were not large. With respect to compounds with potential bioactive properties, coenzyme Q10, and taurine levels were higher in pork from NZ pigs, and carnosine levels were highest for the NZ intensive group (P<0.05). The LL muscle contained more coenzyme Q10 and taurine, but less carnosine than the SM muscle (P<0.001). It is concluded that some of these composition differences in the pork from the muscles and groups compared may be of commercial importance, but several are likely to have been due to dietary or weight differences.

Influence of freezing and thawing on the hydration characteristics, quality, and consumer acceptance of whole muscle beef injected with solutions of salt and phosphate.

Effects of salt/phosphate injection level (112% or 125% pump), salt level (0.5% or 1.5% salt), and freezing/thawing on hydration characteristics, quality, and consumer acceptance of beef semitendinosus were investigated. All enhancement treatments decreased shear force by 25-35%, but negatively affected colour. Increased salt concentration yielded lower purge and cooking losses, and higher water holding capacity. The higher injection level reduced water binding properties, however, the loss in functionality with higher water addition was overcome with increased salt content. Freezing and subsequent thawing was generally detrimental to colour and water binding properties and tended to increase shear force. Freezing and subsequent thawing did not affect fluid release in steaks held for 1 day before analysis, but resulted in decreased water retention in samples held for 7 days. Holding vacuum packaged steaks for 7 days generally increased package purge and negatively affected colour parameters, although water binding characteristics were improved. Consumer panel results demonstrated a negative effect on juiciness and tenderness where meat subject to low salt/high injection was frozen then thawed - the low salt level was insufficient to maintain any positive effect of injection treatment. In general, salt/phosphate injection improved product acceptability and increased willingness to purchase.

The influence of diets supplemented with conjugated linoleic acid, selenium, and vitamin E, with or without animal protein, on the quality of pork from female pigs.

Pork from the LM and semimembranosus muscle (SM) of 59 female Duroc-cross pigs with a mean carcass weight of 80.1 kg (SD = 3.2) were assessed for quality. The pigs were grown on diets containing either animal and plant products (the animal group) or plant products only (the plant group), with or without a supplement (0.31% of the diet) containing extra CLA, selenium, and vitamin E. The 45-min postmortem pH of LM was unaffected by dietary treatment (mean 6.44, SD = 0.21), but the ultimate pH (pHu) was lower for the supplemented animal group for both muscles within the animal group (P < 0.04). Water-holding capacity in terms of drip loss for SM and expressed juice levels for LM, but not cooking loss, was also lower for the supplemented animal group (P < 0.01), but this difference was reduced after adjustment to a constant pHu (P < 0.07). Warner-Bratzler shear force (WBSF) values were greater for the plant group for LM only (P < 0.05), both before and after pHu adjustment. Differences between dietary treatment groups for color (L*, a*, and b*) were small and seldom significant before or after pHu adjustment. Sensory assessment of LM samples (with 5% subcutaneous fat added) from 32 pigs (8 per group) for 8 odor notes and 11 flavor notes by a trained analytical sensory panel of 13 people revealed no differences between the groups, except that the percentage of instances in which a rancid odor was detected was greater for the supplemented plant group compared with the control plant group (25 vs. 12%). Differences (P < 0.001) were shown between the muscles such that, relative to SM, LM had lower pHu values, greater drip losses, greater WBSF values, greater L* values, and lower chroma values, but similar levels of cooking loss. It is concluded that the dietary treatments imposed to improve the nutritional value of pork had some effects on certain meat quality parameters, but that the overall effects on appearance and palatability were small and unlikely to be of practical importance.

The influence of diets supplemented with conjugated linoleic acid, selenium, and vitamin E, with or without animal protein, on the composition of pork from female pigs.

The objective of this study was to evaluate the effect of dietary manipulations on the fatty acid composition, Se content, and vitamin E content of pork. Sixty Duroc-cross gilts were randomly allocated at weaning to 1 of 4 dietary treatment groups (n = 15 per group). The 4 experimental diets were based on animal plus plant components or plant components only, with or without the inclusion of a dietary supplement (0.614%) containing CLA, Se, and vitamin E. The growth performance to approximately 100 kg of BW was similar with diets containing animal plus plant components or only plant components. Growth was also similar when either of these diets included the supplement. Inclusion of the supplement led to expected increases in Se and vitamin E contents (P < 0.001) of the LM. The differences found in the fatty acid profile of the lipid in LM, loin subcutaneous fat, and the belly cut (pork belly) between the groups with and without animal components in their diets largely reflected differences in the diet composition. Inclusion of the supplement led to greater CLA contents in all 3 tissues (P < 0.001), and also to lower contents of oleic acid (P < 0.001) and greater contents of stearic acid (P < 0.05), possibly due to an inhibition of stearoyl-CoA desaturase enzyme. The supplement also led to an increase in LM intramuscular fat (P < 0.05), but did not affect P2 fat depths (65 mm lateral to the midline of the spine at the last rib; mean depth of 11.8 mm). It is concluded that changing from a part animal component diet to an all plant diet will not change the growth performance of pigs but changes in the fatty acid profile of pork are likely to occur. It is further concluded that the nutritional value of pork may be successfully enhanced by simultaneously supplementing the diet with CLA, selenium, and vitamin E.

Preliminary investigation of the effects of low-level dietary inclusion of fragrant essential oils and oleoresins on pig performance and pork quality.

Since the tissue characteristics of monogastric species are readily influenced by the composition of the feeds they consume, the objectives of this preliminary study were to assess the performance of finisher pigs on diets containing 0.05% of essential oils or oleoresins of rosemary, garlic, oregano, or ginger, and to determine the effect of these diets on pork quality. The pigs preferred the garlic-treated diet, and feed intake and average daily gain were significantly increased although no difference in feed efficiency was observed. Carcass and meat quality attributes were unchanged by dietary treatment, although a tendency towards reduction of lipid oxidation was noted in oregano-fed pork. Sensory panelists were unable to detect a flavour/aroma difference between treated and control pork. These results indicate that a higher level of dietary supplementation may be required in order to effect observable differences in pork characteristics.

A mapping method for the description of Warner-Bratzler shear force gradients in beef Longissimus thoracis et lumborum and Semitendinosus.

A novel approach to mapping Warner-Bratzler shear of whole muscles was explored. The procedure was used on the Longissimus thoracis et lumborum (LTL) and Semitendinosus (ST) from six beef cattle by first marking skeletally defined anatomical landmarks on the muscle in situ. After removal from the carcass, further divisions were made while preserving sample orientation during cooking and preparation for shearing. Shear gradients were observed in all planes of the LTL, particularly the medial-lateral. The mid-section of the ST had the lowest shears while superficial locations of the cross-section had greater values. Muscle comparison indicated the ST was more uniform than the LTL. The mapping technique was subsequently used to identify localized effects of altered carcass suspension on shear values and sarcomere length in the lumbar Longissimus from four beef cattle. This mapping method will provide guidance for further intensive investigation across the carcass musculature and under varying carcass conditions.

The effect of modified atmosphere packaging with carbon monoxide on the storage quality of master-packaged fresh pork.

Modified atmosphere packaging with carbon dioxide is effective for prolonging shelf-life of fresh meat. Addition of carbon monoxide to the system provides the advantage of enhancing meat colour. The study objective was to determine the effect of CO(2)-MAP+0.4% CO, vs. 100% CO(2)-MAP, on the bacteriology and colour of retail-ready fresh pork stored for 8 weeks in a master-package system. Total plate counts were not affected and listeria was present on meat from both treatments. Colour was enhanced with the inclusion of CO, while no effect on lipid oxidation was observed. Use of CO in MAP provides sufficient storage life and product colour quality to permit shipment of fresh pork to distant markets. However, given the stable fresh colour of CO-treated meat and the lack of inhibition of pathogen growth by CO, there is concern that CO-MAP under certain conditions may pose a food safety risk.

Palatability of bison semimembranosus and effects of marination.

The present study was conducted to investigate the palatability of bison semimembranosus muscle (SM) and the effects of injection with sodium chloride and sodium tripolyphosphate on cooking yield, colour, shear force and consumer acceptability. Twenty paired SM were obtained from 10 intact male bison (aged 24-30 months); each of these muscles was divided longitudinally into two sections. One section was injected to 110% of its original weight to contain 0.5% sodium chloride and 0.3% sodium tripolyphosphate, while the other was kept as a non-injected control. HunterLab a* (redness) and b* (yellowness) values did not differ (P>0.05) between injection treatments; however, injected steaks had lower L* values (darker) compared to controls. Control samples from bison SM were very lean and high in protein but not very tender. Marination by injection was able to significantly reduce shear force values of SM; that is, injected steaks/roasts had significantly (P<0.001) lower shear force values (63.9 N) compared to control samples (102.3 N). Cooking yields for the steaks/roasts from the injected sections were significantly (P<0.001) higher compared to those from control non-injected sections when cooked to either 71 or 77 °C. Bison samples cooked by moist-heat had significantly (P<0.001) lower cooking losses and shear force values compared to those cooked by dry-heat. As expected, steaks/roasts were more tender and had higher cooking yields when cooked to a medium level of doneness (71 °C) compared to an internal temperature of 77 °C (well done). A panel of 80 consumers preferred injected steaks cooked to 77 °C endpoint over other combinations, followed by non-injected steaks cooked to 71 °C, whereas injected steaks cooked to 71 °C and non-injected steaks cooked to 77 °C were equally but least preferred. Hence, injection seems to be protecting against moisture loss at high end-point cooking temperatures.