Meat Grading Research Articles

Effect of different electrical stimulation systems on beef quality and palatability: Constant current compared to constant voltage

This study examined the effects of constant current electrical stimulation (CCES) compared to constant voltage electrical stimulation (CVES), when applied within the same beef carcass (n = 79), on longissimus thoracis et lumborum (LTL) quality and palatability. There was a stimulation method × time interaction for pH, with CCES reducing the 3 h post-mortem pH, but increasing the 72 h post-mortem pH compared to CVES (P < 0.001). The CCES decreased the meat subjective Japanese Meat Grading Agency (JMGA) colour scores (P < 0.05) and increased the objective L⁎ (P < 0.01), a⁎ (P < 0.05) and b⁎ (P < 0.05) colour values at 3 d post-mortem and L⁎ and b⁎ values (P < 0.05) during retail display compared to CVES, although the objective values from both stimulation methods were above established consumer acceptability thresholds. Additionally, CCES reduced the purge (P < 0.05) and drip (P < 0.01) losses, and tended to reduce shear force values (P = 0.089) compared to CVES, although these did not translate into differences in juiciness or tenderness evaluated by trained panelists (P > 0.1). Regarding flavour, the CCES meat had greater bloody/serumy flavour (P < 0.05) and corn aroma (P < 0.05), less unidentified aroma (P < 0.05), and tended to have greater corn flavour (P = 0.077) and less barnyard aroma (P = 0.079) than CVES meat. There were also increased concentrations of flavour-related volatile compounds including 2-methyl-butanal, 3-methyl-butanal and 2–5-dimethyl pyrazine levels (P < 0.05) with CCES. Overall, the CCES system slightly improved meat quality and flavour compared to CVES when applied to the same beef carcasses. Further consumer studies would be warranted to determine whether these differences translate into more acceptable meat.

Modeling of Ethiopian Beef Meat Marbling Score Using Image Processing for Rapid Meat Grading.

Meat characterized by a high marbling value is typically anticipated to display enhanced sensory attributes. This study aimed to predict the marbling scores of rib-eye, steaks sourced from the Longissimus dorsi muscle of different cattle types, namely Boran, Senga, and Sheko, by employing digital image processing and machine-learning algorithms. Marbling was analyzed using digital image processing coupled with an extreme gradient boosting (GBoost) machine learning algorithm. Meat texture was assessed using a universal texture analyzer. Sensory characteristics of beef were evaluated through quantitative descriptive analysis with a trained panel of twenty. Using selected image features from digital image processing, the marbling score was predicted with R2 (prediction) = 0.83. Boran cattle had the highest fat content in sirloin and chuck cuts (12.68% and 12.40%, respectively), followed by Senga (11.59% and 11.56%) and Sheko (11.40% and 11.17%). Tenderness scores for sirloin and chuck cuts differed among the three breeds: Boran (7.06 ± 2.75 and 3.81 ± 2.24, respectively), Senga (5.54 ± 1.90 and 5.25 ± 2.47), and Sheko (5.43 ± 2.76 and 6.33 ± 2.28 Nmm). Sheko and Senga had similar sensory attributes. Marbling scores were higher in Boran (4.28 ± 1.43 and 3.68 ± 1.21) and Senga (2.88 ± 0.69 and 2.83 ± 0.98) compared to Sheko (2.73 ± 1.28 and 2.90 ± 1.52). The study achieved a remarkable milestone in developing a digital tool for predicting marbling scores of Ethiopian beef breeds. Furthermore, the relationship between quality attributes and beef marbling score has been verified. After further validation, the output of this research can be utilized in the meat industry and quality control authorities.

An electronic equipment for marbling meat grade detection based on digital image processing and support vector machine

This work proposes an electronic equipment which determines the marbling grade in beef rib eye according to the American grading scale using digital image processing and machine learning, achieving an 88.89 % coincidence level with grading done by beef specialists. Existing solutions which use image processing usually require calibration methods due to working in non-controlled environments. Furthermore, they only acquire the fat distribution from the longissimus dorsi muscle with an approximate accuracy of 80 %, without referring the distribution to any quality standard. In this work, meat samples are placed in a food grade stainless-steel enclosure with a touch screen and a digital RGB camera. The device acquires an image of the rib eye, which is then analyzed using techniques such as adaptive histogram analysis based on the HSV color model, histogram peaks detection for grayscale thresholding and a linear Support Vector Machine (SVM). The SVM determines the marbling grade based on the American Standard and shows it via a graphical user interface. The classifier was compared with a k-Nearest Neighbors (kNN) and Random Forest (RF) models, to choose the one with the best performance for marbling grade prediction. The SVM and the kNN models obtained a better performance than RF in identifying the marbling level. The estimated American Standard grade was compared to gold standard reference tests performed by specialists from the National Agrarian University in Lima-Peru, where the SVM achieved the aforementioned 88.89 % coincidence level.

Dynamic correction of dual−energy x-ray absorptiometry images improves chain speed prediction of lamb composition in abattoirs

A prototype, on-line Dual Energy X-ray Absorptiometer (DXA) has shown high precision of the prediction of carcass composition for the purpose of improved sheep meat grading in the Australian lamb supply chain, albeit with small inaccuracies over time. These inaccuracies were present across hours, and more significantly across days, which were unacceptable for any accreditation of this device as an objective carcass measurement tool in Australia. This inaccuracy demanded the creation of a novel image−processing algorithm for the prototype DXA. This DXA was tested for repeatability of predictions of lamb carcass composition over minutes, hours, and days, using two developed image processing algorithms. There was high immediate repeatability for both algorithms when predicting lean muscle % in 40 lamb carcasses, with a maximum CV of 0.65% over five repeated scans. There was a decrease in the CV of the prediction of lean muscle % of 30 lambs scanned three times over a 48-h period from 5.93 to 1.19% when the superior algorithm was used. The inaccuracies of lean muscle % predictions were associated with increases in the unattenuated space pixel values in DXA images. Improvements of the current algorithm are required to demonstrate repeatability over time for the purpose of accreditation within the Australian sheep meat industry, and for possible expansion of this technology into international supply chains.

Dried tomato vines in substitution to alfalfa hay to feed Barbarine lambs: Effects on diet intake, growth performances and carcass quality

Tomato vines are a by-product of tomato plants pruning at different stage of growth and production. Large quantities of tomato vine biomass are produced and accumulated near greenhouses and cause environmental problems. Tomato vines could be used (DTV) as dry roughage to feed livestock. The objective of this study was to evaluate the effects of substituting dried tomato vines (DTV) to alfalfa hay at two levels (50% and 75%) on feed intake, growth performances, non-carcass components, and carcass characteristics of Barbarine lambs. Twenty four 8 months-old Barbarine lambs, with an average weight of 31 kg, were divided into three groups of 8 each and fed diets with different compositions of the roughage portion: the Al100 group received only alfalfa hay as forage, the Al50-T50 group received equal portions of alfalfa hay and DTV, and for the T75-Al25group, the roughage portion was composed of 75% of DTV and 25% of alfalfa hay. All lambs received the same amounts of forage (increasing from 1000 to 1400 g) and the same quantities of concentrated feed (increased from 500 to 700 g). The trial lasted 88 days, after which all of the animals were slaughtered. It was found that substituting DTV to alfalfa hay at the levelof 50% had no effect on roughage and total diet intake. In addition, DTV intake did not affect the slaughter weight (P > 0.05), although the average daily gain and total weight gain were 136 g and 11.5 kg for the Al100 and Al50-T50 groups vs. 125 g and 9.6 kg,; for the T75-Al25 group. Overall, carcass yields and non-carcass components were similar for the three groups of lambs. However, DTV incorporation at the levels of 50% and 75% resulted in leaner carcasses for both tomato groups compared with the Al100 group (54.3 vs.49.9% of muscle and 24.4 vs. 28.8% of fat, respectively). Nevertheless, the highest level of tomato incorporation (75%) promoted the development of the leaner second meat grade (SMCC)(18.2%; P = 0.02) compared to the medium (50%) and null level (0%) of DTV incorporation, which resulted in the same proportion of SMCC(17.5%).

Haematological parameters and production characteristics of novel Romanov × Hissar crossbred sheep adapted to European steppe climate

The study presented some haematological parameters and production characteristics of novel crossbred Romanov × Hissar and purebred Romanov sheep. A number of biochemical and haematological tests were performed to assess the level of adaptation of F1 crossbred progeny to local rearing conditions and evaluate its potential economic benefits for industrial production. The newly created crossbreed demonstrated significant increase in carcass production characteristics, with pre-slaughter weight increased by 29.2%, slaughter weight - by 39.7%, cooled carcass weight - by 40.5% and total yield ‒ by 8.2% compared to Romanov purebreed. The meat quality was also increased: fat content remained at the same level (6.6-6.8%), carcasses of F1 crossbreed lambs had higher relative weight of muscle tissue (78.8% vs. 73.3%), increased content of the 1st grade meat (94.6% vs. 91.6%), and higher caloric value of the meat (by 8.7%) compared to the parent purebreeds. An increased erythrocyte (by 3.1%) and leukocyte (by 6.45%) count was noted in the F1 rams. Haemoglobin level in F1 lambs was increased by 4.2%. Protein metabolism parameters were improved: blood serum total protein level ‒ by 11.2%, albumin ‒ by 11.4%, globulin ‒ by 10.4%, suggesting intensified protein metabolism in F1 lambs; this was also evidenced by the increased activities of aspartate transaminase (by 3.9%) and alanine transaminase (by 16.6%) in F1 lambs over Romanov purebred animals. Blood serum of crossbred lambs had higher bactericidal (by 1.92%), lysozyme (by 3.53%), and phagocytic activity. The increased haematological and biochemical parameters and enhanced antibacterial properties of serum indicate the enhanced metabolic activity in F1 crossbreed sheep and underlay the improved meat production parameters. Obtained results demonstrate increased adaptation of the novel crossbred to industrial rearing conditions and local microclimate of steppe zone of Ukraine, which is undergoing gradual aridization.

Evaluation of dietary curcumin nanospheres as phytobiotics on growth performance, serum biochemistry, nutritional composition, meat quality, gastrointestinal health, and fecal condition of finishing pigs.

Curcumin is a bioactive functional feeding stimulant that is widely used as an additive in cuisine and animal feeds. Owing to its hydrophobic nature and low bioavailability, the nanoformulation of curcumin has recently received special attention from researchers. In this study, we investigated the effects of curcumin nanospheres (CN) on the growth performance, serum biochemistry, meat quality, intestinal immunohistochemistry, fecal malodors and microbes in finishing pigs. A total of 90 crossbred pigs (Duroc × [Yorkshire × Landrace]) with an average initial body weight of 73.77 ± 0.08 kg were randomized into 3 dietary groups in triplicate pens (10 pigs in each pen): control (CON) without supplementation of CN and the pigs in the remaining two groups were supplemented with CN at 1.0 (CN1) and 2.0 (CN2) mL/kg diet for a 40-day long experiment. The results showed that pigs fed the higher CN supplemented diet (CN2) had significantly higher final weight (FW) and weight gain (WG) than those fed the CON diet, and no significant differences were observed in the feed conversion ratio (FCR) and average daily feed intake (ADFI) after 28 days. At the end of the experiment, pigs fed the CN supplemented diet showed no significant difference in WG, ADFI or FCR compared to those on the CON diet. Overall, at the termination of the 40-day feeding trial, dietary CN had a significant effect on FW and WG, except for ADFI and FCR, in finishing pigs. After 40 days of the feeding trial, serum biochemical parameters such as glutamic-pyruvic transaminase, glutamic-oxaloacetic transaminase, triglycerides, and total cholesterol levels were significantly decreased in pigs fed the CN supplemented diet. However, high density lipoprotein levels were significantly increased in pigs fed the CN diets. Protein and lipid contents, as well as yellowness and lightness of the neck and longissimus dorsi muscles were not significantly affected by CN supplementation; however, there was a tendency to increase the redness of the longissimus dorsi muscle in pigs fed the CN2 supplemented diet compared to the CON diet. Meat grading and carcass weight significantly increased in pigs fed a higher CN supplemented diet. Fecal Escherichia coli and ammonia gas were significantly depleted in pigs fed CN diets. Histomorphological parameters, such as villus height, crypt depth and goblet cells in the jejunum of the intestine were significantly increased in pigs fed CN diet. Immunohistochemical staining showed that pro-inflammatory cytokine like tumor necrosis factor-α expression was reduced in pigs fed CN supplemented diets compared to the CON diet; however, antibodies such as immunoglobulin A and tight junction proteins such as claudin 3 were highly expressed in the intestine of pigs fed the CN diets. Overall, the results demonstrate the potential of dietary curcumin nanospheres as a nanobiotechnology tool as well as an effective feed additive for improving the performance and health status of finishing pigs.

Effect of Corn Silage and Soybean Silage Mixture on Rumen Fermentation Characteristics &lt;i&gt;In Vitro&lt;/i&gt; , and Growth Performance and Meat Grade of Hanwoo Steers

Effect of Corn Silage and Soybean Silage Mixture on Rumen Fermentation Characteristics &lt;i&gt;In Vitro&lt;/i&gt; , and Growth Performance and Meat Grade of Hanwoo Steers

The Effects of Total Mixed Ration Feeding with High Roughage Content on Growth Performance, Carcass Characteristics, and Meat Quality of Hanwoo Steers.

This study investigated the dietary effect of total mixed ration (TMR) based on high roughage content on the growth performance, carcass characteristics, and meat quality of Hanwoo steers. Twenty-four Hanwoo steers (average body weight, 195.3±4.7 kg; age, 8.5 mon) were randomly allocated to three experimental groups according to forage and concentrate ratio (DM basis): 25:75 (control), 50:50 (T50), and 70:30 (T70). Productivity in the fattening period and final body weight were significantly higher in the control. Average daily gain and feed conversion ratio were the same among treatments. Serum parameters, cholesterol, blood urea nitrogen, and total protein were higher in the control. Carcass weight was comparable in the control and T50 but feeding more roughage was significantly correlated with a higher intramuscular fat. Shear strength and drip loss were higher while n-6/n-3 was lower in T70 compared to the other groups. However, meat color was not significantly different among treatments. In terms of free amino acid contents, glutamic acid and glycine were higher in the control than T50 and T70. Overall, feeding Hanwoo steers with high forage content TMR had the lowest n-6/n-3 ratio of fatty acid content but highest intramuscular fat, shear strength, and drip loss. High forage content TMR is the best feed for Hanwoo steers that gives more benefits for human health and consumption but also provides the best meat grade and quality, which is important in the beef market in Korea.

Commercial Poultry Production Stocking Density Influence on Bird Health and Performance Indicators.

Simple SummaryPoultry production aims for a stocking density of birds that will promote bird welfare and remain economically efficient. Most research that has examined the link between stocking density and bird welfare has been conducted in experimental facilities with a much smaller area and flock size, compared to commercial facilities. The current study is based on a large set of data from commercial broiler facilities. The results suggest that the stocking density has little impact on the number of mortalities and the quality of the meat. However, we did find increased growth rates at higher stocking densities which contrast with previous published results.This study examines poultry production stocking density (SD) effect on bird welfare and economic performance. It is based on a large dataset from commercial production including observations for 2.2 million male broilers and 2.3 million female broilers from 37 production sites, with SD ranging from 20.63 kg/m2 to 41.15 kg/m2. The data collection was originally motivated by a processor’s economic concerns that increasing SD could cause slower broiler growth, higher condemnations, and lower grade meat. The data was examined using several linear regressions to determine how production parameters impacted these performance indicators. Results regarding foot pad lesion, condemnations, and mortality rates are consistent with those found in the literature. However, we find that daily weight gain is positively associated with SD, contrasting with past experimental results. The difference between the scope of commercial and experimental productions is discussed as a possible reason for these conflicting results.

Autofluorescence excitation-emission matrices as a quantitative tool for the assessment of meat quality.

Commercially produced meat is currently graded by a complex and partly subjective multiparameter methodology; a quantitative method of grading, using small samples would be desirable. Here, we investigate the correlation between commercial grades of beef and spectral signatures of native fluorophores in such small samples. Beef samples of different commercial grades were characterized by fluorescence spectroscopy complemented by biochemical and histological assessment. The excitation-emission matrices of the specimens reveal five prominent native autofluorescence signatures in the excitation range from 250 to 350 nm, derived mainly from tryptophan and intramuscular fat. We found that these signatures reflect meat grade and can be used for its determination.

Productive and breeding qualities of the sheep of Aginskaya breed, Zugalai type

The genetic potential of wool and meat productivity of semi-coarse wool sheep was evaluated for the creation of animal groups that would meet requirements of the desirable type. The article presents the results of the study of productivity and breeding abilities of semi-coarse wool sheep of Aginskaya breed, Zugalai type, belonging to mutton-wool production type. The study was carried out in the pedigree breeding unit of Trans-Baikal Territory. The scope of research was to study productive and breeding qualities of sheep of various age and gender groups. It was established that sheep of Aginskaya breed, Zugalai type, correspond to the elite class by 37.5%, fi rst class – by 51.7% and second class – by 10.8%. Zugalai type semicoarse wool rams exceed the breed standard in live weight by 37.4%, replacement rams – by 38.0%, ewes – by 15.4% and young ewes – by 25.7%, and in terms of pure wool production – by 28.6; 25.0; 7.7 and 8.3%, respectively. Production and yield of wool, its length, morphological composition and fi neness by fractions of semi-coarse wool sheep were identifi ed. The semi-coarse wool of Zugalayan sheep is heterogeneous and consists of fi ne fl eece (79.5-80.6%), medullated fi bers (12.7-13.4%) and coarse hair (6.0-7.8%). The fi neness of fi bers by fractions varies between 21.4-22.9 microns for fi ne fl eece, 39.7-40.2 for medullated fi bers and 72.2-77.3 for coarse hair. The results of the control slaughter of semi-coarse wool rams at the age of 6 months show their reasonably high meat productivity. The slaughter mass of Zugalai type specimens is 18.5 kg, the slaughter yield is 50.9%, fi rst grade meat yield is 92.9%, the meatiness ratio is 3.8.

Meat consumption – what French consumers feel about the quality of beef?

The first aim of this study conducted in France was to examine consumer habits concerning beef consumption, as well as any reasons, which may explain the relative decline in interest in beef consumption. Two surveys were conducted based on a sample of 625 beef consumers to analyse the frequency of their meat consumption and its evolution. The survey also aimed to explore consumers’ understanding of the new labelling system, which was introduced in France in 2015 to indicate the eating quality potential of cuts with stars. Half of the respondents have reduced their beef consumption. Whereas inconsistency in eating quality is one reason among others which contribute to explain this decline, results showed that 70% of the respondents have not seen yet the new labels on beef. Nevertheless, this system represents a major progress for the French beef sector and should be developed further. Indeed, French consumers would be interested in a meat grading system based on tenderness as the one in Australia. Such a system could reduce the decline in beef consumption and even reverse this negative trend.HighlightsThe decline in meat consumption may be explained by the high price of beef, and concerns about health, environment, eating quality and animal welfare.A large proportion of the respondents (72%) is not aware of the new labelling system for beef in supermarket self-service aisles.Further developing this new system to a grading scheme similar to the ‘Meat Standards Australia’ would be judicious.

Analysis of Beef Meat Quality in a Slaughterhouse in Raska District

The quality of slaughtered animals is a subject of interest, for both primary production and the meat industry. Classification of the carcasses is performed in slaughterhouses immediately after a veterinary examination and measurement of the carcasses weight. The present study examined the quality of young cattle carcasses in a slaughterhouse in the Raska district, according to the standard applied in the EU but not in Serbia. In total, 100 cattle carcasses (young bulls) were examined. For meat quality evaluation and grading, the following parameters according to the European standard for the classification of cattle carcasses SEUROP were used: slaughter weight, carcass weight and carcass yield, i.e. the carcass conformation, development of the muscles of the carcass as well as the development of basic parts (round, back and shoulder) and the degree of carcass fat tissue coverage.

The effects of dry or wet aging on the quality of the longissimus muscle from 4-year-old Hanwoo cows and 28-month-old Hanwoo steers

This study was conducted to discover the differences in physicochemical and sensory qualities of beef from 4-year-old Hanwoo cows and 2-year-old Hanwoo steers after undergoing different meat aging methods. Additionally, the possibility of using 4-year-old cows as value-added aged meat was investigated. Loins from eight cows (average 51 months old) and eight steers (average 28 months old) of quality grade 2 were aged for 28 days using dry and wet aging. Analyses were conducted to evaluate meat quality, including moisture content, pH, cooking loss, shear force, nucleotides, free amino acids (FAA), and sensory evaluation. After 28 days of aging, the moisture and shear force for loins from steers and cows were reduced compared with those of non-aged meat (P &lt; 0.05). Cooking loss was reduced by dry aging. Regardless of aging method and gender, aging decreased inosine-5ʹ-monophosphate content but increased FAA content (P &lt; 0.05). Dry aging increased glutamic acid content in meat, and aging the meat of steer increased the content of aspartic acid and glutamic acid (P &lt; 0.05). Before aging, sensory scores for juiciness, tenderness, flavour, and overall acceptance between cow and steer were significantly different (P &lt; 0.05), but the differences disappeared after aging. Therefore, the quality of lower grade meat from 4-year-old cows is comparable to that of meat from 2-year-old steers after aging, regardless of the aging method used.

Impact of pork collagen superfine powder on rheological and texture properties of Harbin red sausage.

Pig skin has cheap price, and easy to get. Pig skin-derived CSPs provide the potential to be used as a good filler and textured modifier available for high quality meat products, including Harbin red sausage.

Studying the effect of gamma irradiation on bovine offal's infected with Mycobacterium tubercullosis bovine type

The presence of microbial pathogens on human foods is a serious global Problem even in highly industrialized and developed countries. The awareness of foodborne diseases by consumers will increase, and therefore, there is a pressure to improve the safety of the food supply. Gamma ray is highly effective in inactivating microorganisms in various foods and offers a safe alternative method of food decontamination. In the present study, a total of 35 samples from T.B. infected carcasses (15 samples of offal's ((7) liver & (8) Kidney) and 15 samples from different lymph nodes((10) Hepatic & (5) Renal)) were collected from some governmental Egyptian abattoirs confirmed to be infected with Mycobacterium tubercullosis bovine type by Real Time PCR were experimental treated with 0.0, 2.5, 5 and 7.5 KGy of gamma rays then, reexamined using RT-PCR for Mycobacterium tubercullosis bovine type infection. The results indicated that the reduction rate is decreased by increase the dose level of Gamma rays. At 0.0 kGy all samples still 100 % infected & 46.6% still infected at 2.5 kGy & 20 % still infected at 5 kGy and, At 7.5 % all examined samples are failed to be detected of T.B. Infected offal's. More ovever, the examined samples of T.B. Infected lymph nodes showed that at 0 kGy all samples still 100 % infected & 53.3 % still infected at 2.5 kGy & 13.3 % still infected at 5 kGy and, at 7.5 % all examined samples are free from mycobacterium infection. The effect on (Color & Odor & Texture) parameter after exposure to Gamma rays on T.B. infected samples proved that most of tested samples have slight changes in color (pale color), odor (characteristic odor of irradiation) and texture (friable) in the first 24 hours and all tested samples have been returned back into the normal parameter after 1 week.The results of the present study showed that it's advisable to use the Gamma irradiation for saving a huge amount of condemned meat due to T.B infected cattle carcasses and using it as low grade meat.

Fast and reliable DNA extraction protocol for identification of species in raw and processed meat products sold on the commercial market

Abstract In this work a protocol for the extraction of DNA from the meat of different animals (beef, pork, and horse) was established. The protocol utilized TE lysis buffer with varying concentrations of phenol and chloroform as a base reagent. Reactions were carried out for verying time periods and under differing temperatures. All samples analyzed were obtained from commercial grade meat sourced from the local region. 12 samples were used for methodological optimization with 30 repetitions per sample. Once optimized, purity results for the three species were 1.7 with a concentration (determined spectrophotometrically at 260 nm) of 100 μl/ml of DNA. The protocol was tested using 465 different meat samples from different animal species. All meat used was fresh and processed. Results showed a purity of 1.35 ± 0.076 and a DNA concentration of 70 ± 0.31 μl for a time duration of 1.5 hours. These results were tested by polymerase chain reaction (PCR) as reported by several authors. The extracts were tested using different PCR reactions using specific primers for horses. Results suggest that there was 39 positive samples. The proposed methodology provides an efficient way to detect DNA concentration and purity, suitable for amplification with PCR.

تشخیص تازگی گوشت گوساله به کمک پردازش تصویر و سطح پاسخ

گوشت و محصولات مرتبط با آن ارزش تجاریی بالایی داشته و یکی از مهمترین اقلام سبد غذایی خانوار را تشکیل می‌دهد. با توجه به عرضه گوشت در قصابی‌ها و نیز استفاده از آن در کارخانه‌های فرآوری نیاز به اطمینان از تازگی آن احساس می‌شود چه بسا گوشت با گذشت از زمان ذبح آن نه تنها از کیفیت آن کاسته می‌شود بلکه ممکن است به سبب فساد موجب بیماری نیز شود لذا هدف از این تحقیق تشخیص تازگی گوشت گوساله با تخمین مدت زمان گذشته از ذبح می‌باشد. برای این منظور از سه قسمت ران، سر دست و گردن گوساله ذبح شده نمونه‌هایی تهیه شد و نمونه‌ها در دو محیط استاندارد و رایج یکی در یخچال با دمای 3 درجه سانتی‌گراد و دیگری در محیط خنک با دمای میانگین 8 درجه سانتی‌گراد نگهداری شد سپس از نمونه‌ها در زمان‌های مشخص (هر 2 ساعت) تصویربرداری شد و از تصاویر تهیه شده توسط پردازش تصویر و به کمک نرم‌افزار MATLAB پارامترهایی استخراج گردید. از بین پارامترهای استخراج شده توسط آنالیز حساسیت سه پارامتر به‌عنوان عامل تأثیرگذار در مدت زمان گذشته از ذبح انتخاب گردید که عبارتند از: خصوصیت بافت، میزان کنتراست و زبری سطح گوشت. در نهایت به کمک روش سطح پاسخ و توسط نرم‌افزارDesign Expert مدل‌های مناسبی تدوین و بهینه گردید.

Fresh Color and pH of Damaged Strip Loins

ObjectivesDamage on beef cuts is usually caused during dressing or trimming of unacceptable superficial areas. On strip loins, subcutaneous fat removal and exposure of lean are the most important causes of damage. Industry quotes obtained in January 2016 revealed that damaged strip loins are approximately marked down US $2.30, US $1.40, and US $1.20 per pound, for USDA Prime, Choice, and Select, respectively. The aim of this study was to evaluate the effect of damage on fresh quality attributes of strip loins.Materials and MethodsTwo different sets of data were collected for this experiment. Set 1– Strip loins (n = 1,149) were allocated to 3 USDA grade treatments (Prime, Choice, and Select) and 2 damage treatments (Damaged and Not Damaged) to evaluate fabrication pH and subjective color. Set 2– Strip loins (n = 256) were allocated to 2 USDA grade treatments (Choice and Select) and 2 damage treatments (Damaged and Not Damaged) to evaluate objective color. For both sets, strip loins were evaluated during fabrication from 18 to 24 h post mortem. Color analysis was performed on the cranial side of the m. Longissimus dorsi. Subjective evaluation was performed according to the Japanese Beef Color Standards (BCS; Japan Meat Grade Association). Objective color was assessed by taking the average of three readings from different areas, acquired with a HunterLab Miniscan XE (CIE L*, a*, and b*). For pH analysis, a Hanna HI99163 pH meter was used. Probe was directly inserted into the m. Longissimus dorsi after taking color evaluation. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC).ResultsHigher percentage of damaged strip loins was observed on USDA Choice, followed by Prime, and Select, 15.99%, 10.20%, and 7.66%, respectively (P ≤ 0.05). No differences were observed on pH from damaged and not damaged strip loins, 5.58 and 5.57, respectively (P = 0.54). Damaged strip loins had brighter color based on BCS when compared to not damaged, 3.7 and 4.1, respectively (P ≤ 0.05). No interaction between main effects USDA grade and damage was observed for objective color. However, damaged strip loins had significant lower values of a* (redness) and b* (yellowness) when compared with not damaged (a* = 26.75 and 24.72; b* = 22.99 and 21.55; for not damaged and damaged, respectively). No significant difference was observed for L* values (lightness).ConclusionMinimal differences on fresh quality attributes were observed between damaged and not damaged strip loins. Differences on color do not impact visual preference. New alternatives about how to optimize the use of damage cuts such as portioning for case ready or creating center cut portions from a damaged strip loin, can eliminate economic losses and still add value on final products.