Paz Lavín

Application of near infrared reflectance spectroscopy to predict meat and meat products quality: a review.

Over the past three decades, near infrared reflectance (NIR) spectroscopy has been proved to be one of the most efficient and advanced tools for the estimation of quality attributes in meat and meat products. This review focuses on the use of NIR spectroscopy to predict different meat properties, considering the literature published mainly in the last decade. Firstly, the potential of NIR to predict chemical composition (crude protein, intramuscular fat, moisture/dry matter, ash, gross energy, myoglobin and collagen), technological parameters (pH value; L*, a*, b* colour values; water holding capacity; Warner-Bratzler and slice shear force) and sensory attributes (colour, shape, marbling, odour, flavour, juiciness, tenderness or firmness) are reviewed. Secondly, the usefulness of NIR for classification into meat quality grades is presented and thirdly its potential application in the industry is shown. The review indicates that NIR showed high potential to predict chemical meat properties and to categorize meat into quality classes. In contrast, NIR showed limited ability for estimating technological and sensory attributes, which may be mainly due to the heterogeneity of the meat samples and their preparation, the low precision of the reference methods and the subjectivity of assessors in taste panels. Hence, future work to standardize sample preparation and increase the accuracy of reference methods is recommended to improve NIR ability to predict those technological and sensory characteristics. In conclusion, the review shows that NIR has a considerable potential to predict simultaneously numerous meat quality criteria.

Ability of near infrared reflectance spectroscopy (NIRS) to estimate physical parameters of adult steers (oxen) and young cattle meat samples

The potential of NIRS-based models to predict several physical parameters of oxen and young cattle beef protected by a quality mark was evaluated. Fifty-three and 67 samples of Longissimus thoracis muscle corresponding to oxen and young cattle reared in extensive conditions were analyzed for pH, colour (L(∗), a(∗), b(∗)), water holding capacity (WHC) and Warner-Braztler shear force (WBSF), according to the conventional methods. Several factors which might have jeopardized the prediction of pH, a(∗), WHC and WBSF by NIRS are considered in the discussion section. However, the best NIR calibrations, tested by full cross-validation, were for L(∗) (R(2)=0.869; SE(CV)=1.56) and b(∗) (R(2)=0.901; SE(CV)=1.08) colour parameters in meat samples from young cattle. It can be concluded that NIRS could be a useful tool for estimating the colour of young cattle meat samples, primary consideration for consumers when making purchasing decisions.

Potential use of near infrared reflectance spectroscopy (NIRS) for the estimation of chemical composition of oxen meat samples

Near infrared reflectance spectroscopy (NIRS) was evaluated as a tool to estimate several chemical parameters of oxen meat protected by a quality mark. Fifty-three samples of longissimus thoracis muscle corresponding to oxen reared in extensive conditions were homogenized and scanned over the NIR spectral range (1100-2500nm). Immediately after scanning, the samples were analyzed for crude protein (CP), myoglobin, collagen, ether extract (EE), gross energy (GE), dry matter (DM) and ash content, according to the official methods. Best NIR calibrations for chemical composition tested by cross-validation showed R(2) and SE(CV) of 0.874 and 20.33gkg(-1) DM (CP), 0.924 and 16.22gkg(-1) DM (EE), 0.941 and 0.293MJkg(-1) DM (GE) and 0.874 and 6.75gkg(-1) FM (DM). Calibrations for myoglobin, collagen and ash content showed a poor predictability, probably as a consequence of the lack of correlation between these parameters and EE content. However, NIRS technology could be an useful tool for estimating the main chemical parameters of oxen meat samples, thus guaranteeing the standards of quality marks.

Animal performance and chemical body composition of lambs fed diets with different protein supplements

Abstract Thirty six Merino lambs with average initial live weight of 13.5 kg (SE±0.56 kg) were used in a 3×3 factorial arrangement (4 lambs per group). The treatments were three concentrate supplements (barley [B], barley 82.5% plus soybean meal 14.5% [BSM] and barley 82.5% plus meat meal 14.5% [BMM]) and three slaughter weights (20, 25 and 30 kg live weight). The lambs fed the B diet consumed less concentrate supplement (0.701 vs. 0.780b and 0.758b kg DM day −1 , P −1 , P −1 LW gain, P P −1 DM), there were no differences ( P >0.05) in crude protein intake between BSM and BMM. (171.0 vs. 179.7 g crude protein day −1 ). The source of dietary protein (soybean meal vs. meat meal) did not have a significant influence ( P >0.05) on performance and chemical body composition of lambs. The interactions between the effect of slaughter weight and the concentrate supplement were non-significant ( P >0.05). This study suggests that meat meal can successfully replace soybean meal as a protein supplement for growing lambs from weaning to 30 kg live weight and offer an alternative to soybean meal as a regional protein source for lamb diets.

Discrimination of adult steers (oxen) and young cattle ground meat samples by near infrared reflectance spectroscopy (NIRS)

Near infrared reflectance spectroscopy (NIRS) was used to discriminate different types of ground beef samples. Fifty-three and sixty-seven samples of longissimus thoracis muscle corresponding to adult castrated steers (over 4 years old) and young cattle (under 14 months old), respectively, were homogenized and scanned over the NIR range (1100-2500nm). The results showed that NIRS could successfully discriminate 100% of ground beef samples depending on the sort of animal, probably as a consequence of differences in the intramuscular fat and water contents. Thus, NIRS is a fast, inexpensive, and non-destructive method that can be used to discriminate these beef products.

Effects of feeding strategy during a short finishing period on performance, carcass and meat quality in previously-grazed young bulls

Twenty-one Brown Swiss×Limousin young bulls reared on pasture were housed for a short finishing period (60 days). CA group (concentrate-ad libitum group) received concentrate and straw ad libitum for the whole finishing period. CR group (concentrate-restricted group) received 4kg of concentrate/animal per day and ad libitum alfalfa hay throughout the 60days. CRA group (concentrate-restricted/ad libitum group) received the same diet as CR group for the first 30days and the same diet as CA group for the last 30days. CA and CRA groups presented higher fatness values. Myoglobin concentration in muscle was highest in CA group (P<0.05) and carotene content in subcutaneous fat was highest in CR group (P<0.01), while Warner-Bratzler shear force and sensory traits were unaffected (P>0.05). It is concluded that, in this type of young animal, 4kg concentrate plus ad libitum alfalfa hay for a 60-day finishing period, despite lower fatness, provides carcasses and meat with acceptable quality characteristics, similar to those obtained from ad libitum fed animals for the same period.

Horse-meat for human consumption — Current research and future opportunities

The consumption of horse-meat is currently not popular in most countries, but because of its availability and recognized nutritional value consumption is slowly increasing in several western European countries based on claims that it could be an alternative red meat. In this review, horse-meat production, trade and supply values have been summarized. In addition, the advantage of horse production is noted because of its lower methane emissions and increased uptake, particularly of n-3 polyunsaturated fatty acids (PUFAs), which is based on its digestive physiology. Of particular interest in this review is the unique fatty acid composition of horse-meat with its high level of the nutritionally desirable PUFAs in both the adipose and muscle fat. Because of its large frame size and digestive physiology, the horse can be considered an alternative to bovine meat, with large advantages regarding the maintenance of less favored mountain grazing areas and its facility to transfer PUFA from feed to meat.

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.

Influence of dietary grape pomace combined with linseed oil on fatty acid profile and milk composition

Grape pomace is a by-product resulting from the winery industry that is rich in phenolic compounds. It could play a role as an antioxidant and, owing to its high fiber concentration, it would be an alternative ingredient to partially replace forage in the diet of small ruminants. The objective of this study was to evaluate the effect of dietary supplementation of vitamin E or different doses of grape pomace associated with linseed oil on milk fatty acid profile, composition, and yield. Forty-eight Churra ewes were fed with experimental diets consisting of a total mixed ration (TMR) containing 2.7% [on a dry matter (DM) basis] of linseed oil, forage, and concentrate at a 40:60 ratio. Ewes were assigned to 1 of 4 treatments: control (without grape pomace), vitamin E (with 500 mg/kg of TMR of vitamin E), grape pomace-5 (5 g/100 g of TMR of DM of grape pomace), and grape pomace-10 (10 g/100 g of TMR of DM of grape pomace). Experimental diets did not affect DM intake and milk yield and composition. The vitamin E supplementation had only a moderate effect on milk concentration of fatty acids (increase in α-linolenic acid and 16:0 and decrease in cis-9 18:1). Grape pomace supplementation did not affect the percentages of total saturated, monounsaturated, and polyunsaturated fatty acids. Levels of α-linolenic acid reached about 1% of total fatty acids as a consequence of the presence of linseed oil in the diets, were not modified with vitamin E, and remained unaltered in grape pomace-5 and -10 treatments. Linoleic acid was increased by the highest dose of grape pomace, but this ingredient did not modify the cis-9,trans-11 18:2 milk fat content. The concentration of total odd- and branched-chain fatty acids did not diminish in grape pomace-5 and pomace-10 treatments. The presence of grape residue did not modified the trans-11 18:1 and trans-10 18:1 contents, which might indicate that, under the conditions assayed, this winery by-product would not alter the pathways of rumen conversion of dietary unsaturated fatty acids.

Grape pomace in ewes diet: Effects on meat quality and the fatty acid profile of their suckling lambs

Grape pomace (GP) is an inexpensive natural antioxidant promising as animal feed supplement due to its high content of phenolic compounds. In order to evaluate its effect in lactating ewe rations on meat quality and fat composition of their suckling lambs, 48 Churra ewes were divided into 4 treatments. All animals were fed a ration containing linseed oil (Control) supplemented with Vitamin E or two levels of GP. Lambs were nourished exclusively by suckling until they were slaughtered. Dietary GP did not generate adverse effects on carcasses or lambs meat quality when compared with Control or Vit-E diets. GP improved the water holding capacity of the meat. In addition, lambs meat FA profile was not nutritionally affected with the diets assayed. Hence, the use of GP as a dietary supplement in ewe rations would not have negative effects on meat from suckling lambs.