Sensory colour assessment of fresh meat from pigs supplemented with iron and vitamin E

Dietary iron or inulin supplementation alters iron status, growth performance, intramuscular fat and meat quality in finisher pigs

Forty LW × L pigs (20 boars and 20 gilts) (51.1 ± 0.41 kg) were allocated to a 2 × 2 × 2 factorial design with the respective factors being supplemental organic iron (Fe, 0 and 500 mg/kg), inulin (In, 0 and 50 g/kg) and sex (boars and gilts). After 5 weeks the animals were transported to an abattoir before slaughter and collection of samples. Serum iron was increased by supplemental Fe (28.4 v. 30.9 μmol/L, P = 0.05), although there was an interaction (P = 0.03) such that pigs fed diets with In had lower serum Fe concentrations than those without In (26.8 v. 32.3 μmol/L). Boars had lower (P < 0.01) haemoglobin (116 vs 125), haematocrit (36.7 v. 39.7%) and erythrocyte (6.6 v. 7.1 × 106/mL) concentrations than gilts. Dietary In increased liveweight gain (795 v. 869 g/d, P < 0.02) and carcass weight (62.9 v. 65.2 kg, P < 0.02). Dietary Fe or In supplementation did not improve muscle Longissimus thoracis et lumborum (LTL) total Fe concentration (P > 0.05). Muscle non-heme Fe concentration was higher in Fe-supplemented pigs (P < 0.04) and gilts (P < 0.05) than their counterparts. Muscle heme Fe concentration was greater (3.04 vs 2.51, P < 0.05) in boars than in gilts. The LTL marbling score was greater (P < 0.01) for In-supplemented pigs, and the response was more notable when Fe and In were fed together. These data show that dietary supplementation of Fe increased serum Fe and muscle non-heme Fe concentrations. Supplementation of In at 5% in the diet of finisher pigs improved liveweight gain and the marbling score of pork.

The Impact of the Fresh Pork Display Lamps on the Sensory Response of Consumers to Fresh Pork

Two studies were conducted to investigate the impact of fresh pork display lamps on consumers' sensory responses to pork products. In the first experiment, 63 participants were asked to evaluate pork products with different degrees of freshness under four fresh pork display lights and two LED lights. In the other experiment, 30 subjects participated in the Farnsworth-Munsell 100 hue test under the same lamps, with the aim of showing whether the fresh pork display lamps impaired color discrimination. The results showed that the light source had a significant effect on the color appearance evaluation of the pork products. The ratings for perceived freshness under the fresh pork display lamps were significantly higher than those of ordinary LED lamps, while the color discrimination performance of the subjects under those lamps was poor. It was demonstrated that improper component proportions of the light spectrum could influence observers' assessment of meat quality and weaken the observers' ability to distinguish the freshness level. Through this study, the authors would like to remind lamp users and manufacturers to not only be concerned about the improvement in the color appearance of pork, but also the need for consumers to be aware of the authentic freshness of the pork products.

Enhancing the Nutritional Value of Red Meat through Genetic and Feeding Strategies

Consumption of red meat contributes to the intake of many essential nutrients in the human diet including protein, essential fatty acids, and several vitamins and trace minerals, with high iron content, particularly in meats with high myoglobin content. Demand for red meat continues to increase worldwide, particularly in developing countries where food nutrient density is a concern. Dietary and genetic manipulation of livestock can influence the nutritional value of meat products, providing opportunities to enhance the nutritional value of meat. Studies have demonstrated that changes in livestock nutrition and breeding strategies can alter the nutritional value of red meat. Traditional breeding strategies, such as genetic selection, have influenced multiple carcass and meat quality attributes relevant to the nutritional value of meat including muscle and fat deposition. However, limited studies have combined both genetic and nutritional approaches. Future studies aiming to manipulate the composition of fresh meat should aim to balance potential impacts on product quality and consumer perception. Furthermore, the rapidly emerging fields of phenomics, nutrigenomics, and integrative approaches, such as livestock precision farming and systems biology, may help better understand the opportunities to improve the nutritional value of meat under both experimental and commercial conditions.

Efeito da suplementação de suínos em terminação com diferentes associações entre minerais sobre o desempenho, as características de carcaça e a viabilidade econômica

RESUMO Objetivou-se, com este estudo, verificar a influência da suplementação com diferentes associações entre minerais orgânicos sobre o desempenho e as características de carcaça, bem como avaliar sua viabilidade econômica, para suínos em terminação. Foram utilizados 88 machos castrados, divididos entre quatro tratamentos: controle com dieta basal e suplementação com CrFe, MgSe e CrFeMgSe, durante os 28 dias que antecederam o abate. O delineamento experimental foi em blocos ao acaso, com parcela experimental representada por dois animais. Os animais suplementados com CrFeMgSe apresentaram piores índices de peso final, ganho de peso diário e consumo durante todo o período, com consequente redução no peso de carcaça, menor profundidade de lombo, área de olho-de-lombo e menor quantidade de carne magra na carcaça. Houve um aumento no custo da dieta para os grupos CrFe, MgSe e CrFeMgSe, respectivamente. O uso de cromo mais ferro e magnésio mais selênio, associados dois a dois, não altera os parâmetros de desempenho e as características de carcaça. A associação dos quatro minerais, no entanto, promove piora nessas características e aumenta o custo da dieta.

Systematic study of the quality and safety of chilled pork from wet markets, supermarkets, and online markets in China

BACKGROUND

With increasing media coverage of food safety incidents, such as that of clenbuterol residues in pork, food safety has become a major public health concern in China. Rapidly developing online markets attract increasing numbers of Chinese consumers to purchase food on the Internet. However, the quality and safety of food sold online are uncertain and are less reported on.

OBJECTIVE

This research aimed to systematically study the quality and safety of chilled pork from wet markets, supermarkets, and online markets in China.

RESULTS

The chilled pork samples from online markets were fresher than those from wet markets and supermarkets based on the surface redness (a* value). Chilled pork contained high levels of nutritional elements, especially the magnesium and phosphorus levels in samples from online markets. The levels of heavy metal element residues and veterinary drug residues in all chilled pork samples were within the standards limits. In addition, huge differences existed in the quality and freshness of the chilled pork samples from online markets according to principal component analysis (PCA).

CONCLUSIONS

Most chilled pork sold in Chinese markets was qualified and safe. It is necessary to establish an effective online market supervision system for chilled pork.

Dietary supplementation with sunflower seeds and vitamin E for fattening lambs improves the fatty acid profile and oxidative stability of the Longissimus lumborum

This study aimed to evaluate the effects of supplementation with sunflower seeds and vitamin E for fattening lambs, on the chemical composition, cholesterol, vitamin E level, fatty acid profile and lipid oxidation of meat from sheep. Four treatments were evaluated, as follows: SC – basal diet consisting of sugarcane + concentrate; SCS – basal diet supplemented with sunflower seed; SCE – basal diet supplemented with 1000 mg vitamin E; SCSE – basal diet supplemented with sunflower seed and 1000 mg vitamin E. The Longissimus lumborum muscle of 32 Ile de France lambs, which were slaughtered when their bodyweight reached 32 kg, was used. The chemical composition of the lamb meat was not significantly different (P > 0.05) between the treatments. Sunflower seed supplementation increased (P < 0.05) the levels of linoleic acid, vaccenic acid and conjugated linoleic acid. Inclusion of vitamin E in the diet increased (P < 0.05) the concentration of vitamin E in the meat while decreasing lipid oxidation. Considering the current demand for healthy foods, inclusion of sunflower seeds and vitamin E in the diet of sheep is a viable possibility.

Oxidative and colour changes in meat from three lines of free-range reared Iberian pigs slaughtered at 90 kg live weight and from industrial pig during refrigerated storage

The oxidative stability and colour evolution during refrigerated storage (10 days at +4 °C) of Longissimus dorsi muscle from three lines of Iberian pigs and industrial genotype pigs were studied. The Iberian pigs were reared in an extensive system and fed on a commercial feed with access to pasture grazing, while industrial genotype pigs were reared in an intensive system. Fresh Longissimus dorsi of Iberian pig lines showed a more intense and redder colour, with a statistically significant higher CIE chroma and a*-value as well as a lower L*-value (P<0.05) compared with those of industrial genotype pigs. Pig genotype significantly affected the colour and lipid oxidation changes of m. Longissimus dorsi during refrigerated storage. The decrease in L*-value during the refrigerated storage was more intense in industrial pig's Longissimus dorsi than in those from Iberian pig lines. CIE a*-value decrease was more intense in 'Lampiño' Iberian line and industrial Longissimus dorsi than in the other two Iberian pig lines, however CIE a*-value was significantly higher in muscles from Iberian pig lines than in muscle of industrial genotype (P<0.05) at the end of refrigerated storage. The Iberian and industrial pig's Longissimus dorsi did not show statistically significant differences in TBA-RS values (mg MDA/kg meat) at the end of the refrigerated storage period (P>0.05). To establish relationships between parameters measured in fresh meat and oxidation and colour changes during refrigerated storage, correlations and multiple regression models were calculated. CIE a*-values at day 10 were positively correlated with values of fresh muscles for a*, C18:1 percentages and negatively correlated with polyunsaturated fatty acids percentages of neutral and polar lipids. Inversely, TBA-RS values at day 10 showed a positive correlation with initial values for phospholipid content and polyunsaturated fatty acids of neutral and polar lipid fractions, while C18:1 percentage were negatively correlated.

Effect of supplemental iron on finishing swine performance, carcass characteristics, and pork quality during retail display1

Crossbred pigs (n = 185) were used to test the effects of dietary Fe supplementation on performance and carcass characteristics of growing-finishing swine. Pigs were blocked by BW, allotted to pens (5 to 6 pigs/pen), and pens (5 pens/block) were allotted randomly to either negative control (NC) corn-soybean meal grower and finisher diets devoid of Fe in the mineral premix, positive control (PC) corn-soybean meal grower and finisher diets with Fe included in the mineral premix, or the PC diets supplemented with 50, 100, or 150 ppm Fe from Availa-Fe (an Fe-AA complex). When the lightest block averaged 118.2 kg, the pigs were slaughtered, and bone-in pork loins were collected during fabrication for pork quality data. During the grower-I phase, there was a tendency for supplemental Fe to reduce ADG linearly (P = 0.10), whereas in the grower-II phase, supplemental Fe tended to increase ADG linearly (P = 0.10). Even though pigs fed NC had greater G:F during the finisher-I phase (P < 0.05) and across the entire trial (P = 0.07), live performance did not (P > or = 0.13) differ among dietary treatments. There were linear increases in 10th-rib fat depth (P = 0.08) and calculated fat-free lean yield (P = 0.06); otherwise, dietary Fe did not (P > 0.19) affect pork carcass muscling or fatness. Moreover, LM concentrations of total, heme, and nonheme Fe were similar (P > 0.23) among treatments. A randomly selected subset of loins from each treatment was further fabricated into 2.5-cm-thick LM chops, placed on styrofoam trays, overwrapped with polyvinyl chloride film, and placed in coffin-chest display cases (2.6 degrees C) under continuous fluorescent lighting (1,600 lx) for 7 d. During display, chops from NC-fed pigs and pigs fed the diets supplemented with 100 ppm Fe tended to have a more vivid (higher chroma value; P = 0.07), redder (higher a* value; P = 0.09) color than LM chops of pigs fed 50 ppm of supplemental Fe. Moreover, greater (P < 0.01) redness:yellowness ratios in chops from pigs supplemented with 100 ppm Fe indicated a more red color than chops from PC-fed pigs or pigs fed diets supplemented with 50 ppm Fe. In conclusion, however, increasing dietary Fe had no appreciable effects on performance, carcass, or LM characteristics, suggesting that current dietary Fe recommendations are sufficient for optimal growth performance, pork carcass composition, and pork quality.