Cooked Beef Samples Research Articles

Influence of overcooking on in vitro digestion and fermentation of ground beef and whole wheat bread

Areas of char or overcooking commonly appear in foods people consume. It has been reported that overcooked food is harmful to human health. However, little research exists on the effect of overcooking on digestible protein and starch content and gut microbial fermentation. This study aimed to reveal the connection between overcooking and the content of digestible protein and starch, as well as its impact on gut microbial fermentation. Digestible protein in the standard cooked ground beef patty was significantly higher than the overcooked samples (p = 0.009). Standard-cooked whole wheat bread also showed a significantly higher digestible protein content compared with overcooked (p = 0.009). A significant difference was also found in digestible starch content between standard cooked and overcooked bread samples (p = 0.02). Overcooking decreased acetate, propionate, iso-butyrate, iso-valerate and ammonia production by the gut microbiota during fermentation of the beef sample, and decreased propionate and ammonia production during fermentation of the bread sample (p < 0.05). Interestingly, overcooking enhanced butyrate production by the microbiota during fermentation of the bread sample (24 h of fermentation, p < 0.001; 48 h of fermentation, p = 0.02), while no significant difference was found between overcooked and standard cooked beef samples (24 h of fermentation, p = 0.15; 48 h of fermentation, p = 0.4). Overcooking resulted in reductions in many Pseudomonadota and favored several Bacillota, especially Ruminococcaceae and Oscillospiraceae, which contain butyrate producers. Overall, overcooking reduced digestible protein, digestible starch, and fermentation of proteins. Unexpectedly, overcooking induced several purportedly favorable effects on the gut microbiota due to the decreased protein fermentation, which, in future studies, should be weighed against the previous reports that overcooking is deleterious to human health.

Antibacterial Mode of Eucommia ulmoides Male Flower Extract Against Staphylococcus aureus and Its Application as a Natural Preservative in Cooked Beef.

The research was conducted to elucidate the antibacterial performance and mode of action of Eucommia ulmoides male flower extract (EUMFE) against Staphylococcus aureus and its application as a natural preservative in cooked beef. The antibacterial activity was evaluated by determining the diameter of inhibition zone (DIZ), minimum inhibitory concentration (MIC), and minimum bactericide concentration (MBC). The changes in membrane potential, contents of bacterial DNA and protein, integrity and permeability of the cell membrane, and cell morphology were analyzed to reveal the possible mode of action. The effect of EUMFE on the counts of S. aureus, pH, color, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) of the cooked beef stored at 4°C for 9 days were studied. The results showed that the DIZ, MIC, and MBC of EUMFE against S. aureus were 12.58 ± 0.23 mm, 40 mg/mL, and 80 mg/mL, respectively. The mode of action of EUMFE against S. aureus included hyperpolarization of cell membrane, decrease in bacterial DNA and protein contents, destruction of cell membrane integrity, increase in cell membrane permeability, and damage of cell morphology. After treatments with EUMFE, the growth of S. aureus and lipid oxidation in cooked beef were significantly inhibited (P < 0.05). The pH and TVB-N values of cooked beef treated with EUMFE were significantly reduced as compared to control group (P < 0.05). The color of cooked beef samples containing EUMFE showed decreased L* and b* values, and increased a* and ΔE* values. Therefore, our findings showed that EUMFE had a good antibacterial effect on S. aureus, and provided a theoretical basis for the application of EUMFE as a natural preservative in the preservation of cooked beef.

Microbiological evaluation of Vietnamese Pho ingredients in Toronto

Introduction: Beef and bean sprouts have often been implicated in foodborne illness (FBI) outbreaks. The traditional Vietnamese dish, Pho, uses both as its main ingredients and, therefore, presents significant concerns from a food safety perspective. The present study investigated food safety concerns associated with Pho through the detection of total coliform and Escherichia coli. Methods: Thirty-two Vietnamese restaurants in Toronto, Ontario, Canada, were selected for the study based on inclusion criteria. All restaurant operators were briefed prior to sampling and were informed that their consent and participation were voluntary. Fourteen restaurants consented to providing samples and allowing their broth temperatures to be taken. Three types of samples were obtained from each location: raw beef (RB), cooked beef (CB), and bean sprouts (BS). All samples were couriered to an accredited laboratory for microbiological analysis via 3M petrifilm E. coli/coliform count plates. Based on reported total coliform count (TCC), locations were segmented into low, medium, and high contamination categories. Subsequent correlational analysis were conducted based on lab detection data to identify potential links between E. coli count (ECC) and TCC, TCC and broth temperature, and ECC and broth temperature. In addition, an ANOVA was performed to examine for differences in TCC by sample types, differences in TCC by suppliers, differences in ECC by sample types, differences in ECC by suppliers, and differences in TCC by location types. Results: ANOVA indicated a significant effect of sample type on TCC for all three different sample types, with post hoc comparisons elucidating significantly lower TCC in CB and RB samples, compared with BS samples. Subsequent analysis further indicated the significant effect of location category on TCC, with post hoc comparisons demonstrating significantly higher TCC in Category 3 locations compared to Category 1 and 2 locations. All other analysis yielded nonstatistically significant results. Conclusion: This study presented significant findings in linking Pho ingredients to potential food safety concerns. Specifically, temperature control was identified as a possible cause for high TCC and E. coli detection at select restaurants. Although analysis involving E. coli did not yield any significant results, any E. coli found on ready-to-eat food at a restaurant is problematic from a food safety perspective. Based on the results, we recommended policy changes to incentivize restaurants to maintain high hygienic standards and improve efficiency of the public health inspection process.

Chemical Characterization and Sensory Relationships of Beef M. longissimus lumborum and M. gluteus medius Steaks After Retail Display in Various Packaging Environments

Volatile compounds, carbonyls, non-heme iron, and thiobarbituric acid reactive substances (TBARS) were measured in both raw and cooked beef samples to determine the effects of muscle and packaging type on beef flavor development. All paired strip loins and top sirloin butts were packaged under vacuum and aged for 14 d postmortem. After initial aging, all subprimals were fabricated to produce M. gluteus medius (GM) or M. longissimus lumborum (LL) steaks. At 14 d postmortem, steaks were randomly assigned to 1 of 5 package types: high-oxygen modified atmosphere lidded trays (80% O2/20% CO2 [“HIOX”]), carbon monoxide modified atmosphere lidded trays (0.4% CO/30% CO2/69.6% N2 [“CO”]), rollstock (forming and non-forming films [“ROLL”]), vacuum packaging without retail display (“VAC”), and traditional overwrap (“OW”) remained under vacuum prior to retail display. Steaks were stored in darkness an additional 7 d prior to display. At 21 d postmortem, HIOX, OW, CO, and ROLL packages were displayed for 48 h under continuous fluorescent lighting, while VAC steaks remained in dark storage. Packaging and muscle type impacted (P &amp;lt; 0.05) quantities of multiple volatile flavor compounds, including alcohols, n-aldehydes, esters, furans, hydrocarbons, sulfur-containing compounds,and ketones in both raw and cooked samples. Volatile compounds related to lipid oxidation were more (P &amp;lt; 0.05) prominent in HIOX packaging. Package type (P &amp;lt; 0.05) and muscle (P &amp;lt; 0.05) had an impact on raw-steak TBARS, although package type did not influence (P &amp;gt; 0.05) cooked-steak TBARS. The GM possessed greater (P &amp;lt; 0.05) TBARS values than the LL in both raw and cooked samples. Package type had no effect (P &amp;gt; 0.05) on carbonyl and non-heme iron content although these analyses differed among muscles (P &amp;lt; 0.05), with the GM being greater (P &amp;lt; 0.05) than the LL. These results indicate that the development of lipid oxidation that occurs during storage and display was muscle and packaging specific. Therefore, to maintain flavor, quality packaging systems should be selected on a muscle-specific basis.

Increased protein digestibility of beef with aging in an infant in vitro digestion model

This study investigated the protein digestibility of aged beef using an infant in vitro digestion model. Semitendinosus muscles were vacuum-packed and aged for 0, 7, and 14 days at 4°C. Malondialdehyde content of raw and cooked beef increased with aging (P < .05). However, no changes in carbonyl content were observed for aged raw and cooked beef samples. The α-amino group content and myofibrillar fragmentation index of beef increased with aging (P < .05). The α-amino group content of cooked beef digesta increased upon aging (P < .05). Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed the decrease in band intensities of actin in the digesta of aged beef. These results highlight the improvement in the protein digestibility of beef aged for 7 and 14 days. Therefore, aged beef is more desirable as complementary food owing to increased protein digestibility.

Frequency of hemolysin BL and non-hemolytic enterotoxin complex genes of Bacillus cereus in raw and cooked meat samples in Zanjan, Iran

Food safety has emerged as an important global issue with international trade and public health implications. Bacillus cereus is an important cause of food poisoning worldwide. A total of 200 individual meat samples were collected from meat retail outlets and restaurants and investigated the frequency of B. cereus and hemolysin BL (Hbl), non-hemolytic enterotoxin (Nhe) complex genes. The meat samples were immediately homogenized and cultured on Bacillus cereus selective agar and subjected for confirmatory biochemical tests and molecular detection of gyrB, hblA, hblC, hblD, nheA, nheB and nheC genes. A total of 29 (14.5 %) meat samples were positive for the presence of B. cereus. The frequency of B. cereus in raw meat (14.1 %) was similar to cooked beef samples (15 %) (P > 0.05). Twenty six (89.6 %) isolates carried at least one or more enterotoxin genes. We found nheA (58.6 %) and hblD (51.7 %) genes with higher frequency than others. Hemolysin BL complex genes were found in lower frequency than Nhe complex (P > 0.05). Detection of enterotoxigenic B. cereus in meat samples shows a probable risk for public health. Therefore, the reliable molecular methods for monitoring of potentially pathogenic B. cereus are strongly recommended for the routine food examination.

Horse meat sold as beef and consequent clenbuterol residues in the unregulated Mexican marketplace

The final destination of the large volumes of horse meat produced in Mexico is not apparent. The current study therefore aimed to determine if horse meat is sold fraudulently under the guise of beef in Mexico and the levels of clenbuterol residues in samples. While more than a quarter of the sellers interviewed claim to know of suppliers for horse meat, only 7% would like to sell horse meat. Yet, 10% of the 433 samples tested positive for horse meat. The proportions of raw and cooked beef samples containing horse meat were similar at 9.5% and 11.0%, respectively. Burritos were the meat product in which horse meat was observed most prevalent at 28.6%, varying from 4.9 to 12.9% in the other meat and products. None of the samples from supermarkets tested positive for horse meat, whereas, at 18.2%, horse meat was most prevalent in the restaurant-type establishments. Clenbuterol was observed in all of the raw meat samples containing horse meat.

Effect of ohmic cooking followed by an infrared cooking method on lipid oxidation and formation of polycylic aromatic hydrocarbons (PAH) of beef muscle

In this study, the effects of ohmic cooking alone and a consecutive application of ohmic and infrared cooking on lipid oxidation and polycyclic aromatic hydrocarbon (PAH) formation in beef was investigated. In consecutive cooking, samples were first cooked ohmically at 40, 55 and 70 Volt for 7 minutes, then infrared cooking was applied to each side of ohmically cooked beef samples at 3 different temperatures (325, 375 and 425 °F) for 3 minutes. The thiobarbituric acid reactive substance (TBARS) levels of the samples were found between 0.31 and 1.74 mg MDA/kg. Increasing the voltage level in ohmic cooking caused a significant (P &lt; 0.05) increase in the TBARS value. In the consecutive application of ohmic and infrared cooking, infrared cooking temperature caused a significant (P &lt; 0.05) increase in the TBARS value at the same voltage levels. In this study, working with 40 and 55 Volts for ohmic cooking alone and 40 V-325 °F, 40V-375 °F settings for ohmic-infrared cooking gave a generally acceptable threshold level for TBARS value (1 mg/kg). About 12 polycyclic aromatic hydrocarbons (PAHs) were detected in the cooked beef by ultra-performance liquid chromatography fluorescence detector (UPLC-FD). Benzo(a)pyrene (BaP), which is the most common PAH, was detected at between 1.2514 and 1.4392 μg/kg and 4 PAH (sum of Benzo(a)pyrene, Chrysene, Benz(a)anthracene, Benz(b)fluoranthene) levels were detected at between 1.2514- 3.7844 μg/kg. The results of PAHs were reasonably below the European Commission regulation limits, which are very important and indicate that the cooking processes applied in this study are safe.

Assessment of objective measures of beef steak juiciness and their relationships to sensory panel juiciness ratings.

The objective of this study was to evaluate multiple instrumental measures of beef juiciness and determine their relationships with sensory panel juiciness ratings. Treatments were selected to maximize variation in juiciness and included 5 USDA quality grades (Prime, upper two-thirds Choice, lower one-third Choice, Select, and Standard) as well as 2 enhanced Select treatments (112 and 107% of the initial raw weight) and were prepared to 3 degrees of doneness (DOD; rare [66°C], medium [71°C], and well done [77°C]). A total of 21 objective measures of raw samples were evaluated and included marbling level, CIE color values, pH, water activity, proximate composition, and multiple measures of water-holding capacity. Also, 17 objective measures were evaluated for cooked beef samples and included cooking loss, drip loss, and compression-based methods used to quantify expressible moisture. These measures were compared with results from a previous sensory study to evaluate the relationship between the various objective measures and sensory panel juiciness ratings. Differences ( < 0.05) were found among quality treatments for many of the measures evaluated, with the greatest differences occurring for many of the measures among samples cooked to different DOD. Of all the objective measures evaluated, protein percentage, cooking loss, and pressed juice percentage (PJP) were most closely associated ( < 0.05) with consumer juiciness ratings ( = -0.55, = -0.51, and = 0.45, respectively). Additionally, cooking loss and PJP were more closely associated ( < 0.05) with trained sensory panel initial and sustained juiciness ratings than all other measures evaluated. Regression analysis revealed that PJP explained ( < 0.05) 20, 48, and 45% of the variation in consumer, trained panel initial, and trained panel sustained juiciness scores, respectively. This was a greater percentage of the variation than slice shear force explained ( < 0.05) in trained sensory panel initial (39%) and sustained tenderness ratings (40%) and similar to the amount explained (26%) in consumer tenderness ratings. These results indicate PJP was a better predictor of sensory panel juiciness scores than all traits evaluated other than the cooking loss of steaks evaluated by sensory panelists. Pressed juice percentage explained a similar or greater amount of variation in sensory panel scores as slice shear force, indicating PJP as a potential industry standard for objective juiciness evaluation.

Untrained consumer assessment of the eating quality of beef: 1. A single composite score can predict beef quality grades

Quantifying consumer responses to beef across a broad range of demographics, nationalities and cooking methods is vitally important for any system evaluating beef eating quality. On the basis of previous work, it was expected that consumer scores would be highly accurate in determining quality grades for beef, thereby providing evidence that such a technique could be used to form the basis of and eating quality grading system for beef. Following the Australian MSA (Meat Standards Australia) testing protocols, over 19 000 consumers from Northern Ireland, Poland, Ireland, France and Australia tasted cooked beef samples, then allocated them to a quality grade; unsatisfactory, good-every-day, better-than-every-day and premium. The consumers also scored beef samples for tenderness, juiciness, flavour-liking and overall-liking. The beef was sourced from all countries involved in the study and cooked by four different cooking methods and to three different degrees of doneness, with each experimental group in the study consisting of a single cooking doneness within a cooking method for each country. For each experimental group, and for the data set as a whole, a linear discriminant function was calculated, using the four sensory scores which were used to predict the quality grade. This process was repeated using two conglomerate scores which are derived from weighting and combining the consumer sensory scores for tenderness, juiciness, flavour-liking and overall-liking, the original meat quality 4 score (oMQ4) (0.4, 0.1, 0.2, 0.3) and current meat quality 4 score (cMQ4) (0.3, 0.1, 0.3, 0.3). From the results of these analyses, the optimal weightings of the sensory scores to generate an ‘ideal meat quality 4 score (MQ4)’ for each country were calculated, and the MQ4 values that reflected the boundaries between the four quality grades were determined. The oMQ4 weightings were far more accurate in categorising European meat samples than the cMQ4 weightings, highlighting that tenderness is more important than flavour to the consumer when determining quality. The accuracy of the discriminant analysis to predict the consumer scored quality grades was similar across all consumer groups, 68%, and similar to previously reported values. These results demonstrate that this technique, as used in the MSA system, could be used to predict consumer assessment of beef eating quality and therefore to underpin a commercial eating quality guarantee for all European consumers.

Comparative study of mineral composition of beef steak and pork chops depending on the thermal preparation method

This study focuses on the effects of three different thermal preparation methods (roasting, boiling, and microwave cooking) on the mineral concentrations of beef and pork, as well as on the comparison of mineral levels between these two types of meat. In this study, raw and cooked beef and pork samples were selected and analyzed by ICP-OES in order to determine mineral concentrations. In general, thermal preparation clearly increased mineral concentrations in cooked samples compared to raw meat. The highest mineral concentration was identified in the roasted samples. Trace element concentrations in beef were significantly higher compared to pork. In pork, Na concentration decreased in all samples, suggesting that Na is lost with water. Zn mean content in cooked beef samples registered significant differences compared to pork cooked samples. The percentage of water loss during the microwave thermal preparation for beef samples was higher than the other two treatments.

How do Alternative Pressures Affect the Accuracy of the Pressed Juice Percentage (PJP) at Predicting Consumer Juiciness Rating?

Texture is the most important sensory trait when evaluating meat products (Gomes et al., 2014). In beef products, tenderness and juiciness interact to form overall texture and mouthfeel. As a result, beef juiciness is one of the most important factors in creating a satisfactory beef eating experience. A recent study by Woolley (2014) developed an instrumental technique for measuring beef juiciness and predicting consumer beef juiciness satisfaction. The method utilizes a texture analyzer to compress cooked beef samples for a period of 8 seconds at 17.6 lb of force and quantifies the percentage of moisture lost as Pressed Juice Percentage (PJP), a predictor of beef juiciness. Results from the initial study found PJP accounts for 20% of the variation in consumer juiciness scores; however, an evaluation of additional pressures is needed to determine if the PJP method can account for an even greater percentage of variation. Thus, the objective of this study was to evaluate the PJP method utilizing three different pressures and determine the relationship of these values to consumer sensory scores for juiciness.

Hyperspectral Imaging for Beef Tenderness Assessment

Tenderness is one of the principal properties of meat quality. The traditional way to measure tenderness the beef is time consuming and also destructive, and therefore not appropriate for rapidly identifying quality parameters on the processing line, with the minimum of human intervention. The objective of the present research was to measure the tenderness of cooked beef samples obtained from four types of muscles (i.e. infraspinatus (TB), gluteus medius (TS), psoas major (TL), and longissimus thorasis (RE)) at three different durations of dry aging (Fresh (0 days), 14 days, and 21 days), using near infrared hyperspectral imaging. Hyperspectral reflectance spectra (900 nm <l < 1700 nm) were acquired for a total of 260 beef steak samples with dry-ages of 0, 14 or 21 days. After imaging, samples were cooked and the Warner-Bratzler shear force (WBSF), a parameter inversely related to meat tenderness, was measured. After reflectance calibration, a region of interest (ROI) was selected from each acquired hyperspectral image and stepwise regression was applied to the ROI to select wavelengths that were strongly related to cooked meat tenderness. Multiple Linear Regression (MLR) calibration models were developed for quantitative evaluation of beef tenderness. The correlation coefficient (R) and the root mean square error (RMSE) were employed to evaluate the calibration model’s predictive ability for each group. The calibration model developed predicted tenderness with R values of 0.89, 0.86, 0.81 and 0.83 for TS, RE, TB, and TL, respectively. The results revealed that the HSI could be used for non-destructive measurement of beef tenderness in beef having undergone three different durations of aging.

Applications of Proteolytic Enzymes from Kiwifruit on Quality Improvements of Meat Foods in Foodservice

The purpose of this study was to evaluate kiwifruit as a tenderizer by its effects in improving the quality of various beef parts. Basic data are provided for development of standard recipes for convenient cooking in foodservice. The optimum temperature of the crude proteolytic enzymes in the kiwifruit was determined to be <TEX>$65^{\circ}C$</TEX>. The substrate specificity of the enzymes was higher in beef than in pork, chicken, or duck. The enzymes had their greatest effects on chuck and rib parts, and had lower effects on loin, breast, and round parts, in that order. As the amount of kiwifruit extract increased, the moisture content of the cooked beef also increased. The addition of 10% kiwifruit improved the sensory quality of the cooked beef. In particular, the texture scores of cooked beef samples treated with 10% and 15% kiwifruit extract were significantly higher than the other samples (p<0.001), and juiciness and overall acceptability scores were also highest. In summary, 10% kiwifruit extract is deemed an appropriate addition to improve.

사회인구학적 요인이 1++등급 거세한우고기의 부위 및 요리형태별 관능특성에 미치는 영향

본 연구는 국내에서 최고급육으로 유통되는 육질등급이 <TEX>$1^{++}$</TEX>인 거세한우고기에 대하여 소비자 관능평가를 실시하여 사회인구학적 요인과 한국 소비자들의 관능특성간에 어떠한 관계가 있는지 알아보고, 이 결과를 한국 소비자들을 위한 요리방법 및 부위별 맛 예측 모델을 설정하기 위한 기초자료로 활용하고자 수행하였다. 28-30개월령 거세한우를 도축한 후 업진, 보섭, 채끝, 등심, 꾸리, 홍두깨, 목심, 설깃, 우둔, 양지 부위를 분리하여 전국 소비자 650명을 대상으로 탕, 그릴 및 구이형태로 각각 조리하여 연도, 다즙성, 향미 및 전반적인 기호도를 평가한 결과 탕 형태로 조리된 거세한우고기는 거주지역, 연령, 성별, 직업 및 10개의 부위에 대한 관능특성 4가지 요인(연도, 다즙성, 향미 및 전반적인 기호도)과 모두 관련이 있는 것으로 나타났다. 또한 고기섭취습관 및 숙성여부도 연도 및 전반적인 기호도와 유의적인 연관성이 있는 것으로 나타났다(p<0.01). 스테이크 형태인 경우 쇠고기에 대한 기호 성향이 거주지역, 숙성여부 및 부위가 관능특성 4가지 요인(연도, 다즙성, 향미 및 전반적인 기호도)과 모두 관련이 있는 것으로 나타났으며 연령, 수입 및 고기섭취습관 등도 연도 및 전반적인 기호도 특성이 유의적인 영향을 미치는 것으로 나타났다(p<0.01). 구이 형태인 경우 거주지역, 연령, 직업, 가계수입, 고기섭취 습관, 숙성 여부 및 부위에 따라 연도, 다즙성, 향미 및 기호도 성향에 유의적인 차이가 있었다(p<0.001). 또한, <TEX>$1^{++}$</TEX> 등급과 같은 최상의 육질등급을 받은 거세한우고기의 관능평가 결과에 대하여 주성분 분석을 실시한 결과, 요리방법에 따라 연도, 다즙성, 향미 및 기호도가 부위별 관능특성에 미치는 가중치가 다른 것으로 분석되었다. 결론적으로 한국소비자들은 동일한 조건의 쇠고기일지라도 요리방법 및 부위에 따라 쇠고기 맛을 평가하는 기호도에 차이가 있었으며 이러한 점을 고려하여 부위별 요리방법별 맛 예측모델을 확립한다면 한우고기를 차별화 할 수 있는 유통시스템 개발이 가능할 것으로 생각된다. This study was conducted to investigate the relationship between the socio-demographic factors and the Korean consumers' palatability evaluation and to collect the sensory information for development of prediction palatability model of Hanwoo beef. Ten cuts [Abjin (short plate), Bosup (top sirloin), Cheggt (striploin), Dngsim (loin), Guri (chuck tender), Hongduke (eye of round), Moksim (chuck roll), Sulgit (bottom round), Udoon (top round), Yangji (brisket)] were separated from 5 Hanwoo steer beef (28-30 months old) and prepared with the same manner for 3 different cooking methods such as boiling, grilling, and roasting. The cooked beef samples were served to 650 consumers recruited from Seoul, Joongbu, Honam and Youngnam locations and evaluated as tenderness, juiciness, flavor, and overall acceptability. The consumer living location, age, gender, occupation, monthly income, and cut were significantly related with the scores of sensory properties when steer beef were cooked as boiling cooking (p<0.05). The eating habit and aging of beef were also significantly related with the tenderness and overall acceptability scores (p<0.01) when beef were cooked as boiled. In grill cooking, living location, aging, and cut had the significant effect on the sensory properties of Hanwoo steer beef (p<0.01). When steer beef were prepared by Korean traditional roast cooking, consumer's sensory scores were significantly different by the living location, age, occupation, monthly income, eating habit of consumers, aging and beef cut (p<0.001). Also, results from the principal component analysis showed that palatability scores of Korean consumers were decided with different contribution rate of tenderness, juiciness, flavor and overall acceptability for beef cut depending on cooking methods. In conclusion, Korean consumers' palatability for Hanwoo steer beef were related to the socio-demographic factors and the sensory scores were different by cut and cooking methods.

New method for the analysis of heterocyclic amines in meat extracts using pressurised liquid extraction and liquid chromatography–tandem mass spectrometry

Heterocyclic amines (HAs) were analysed in meat extract samples using a new method based on pressurised liquid extraction (PLE) and liquid chromatography–tandem mass spectrometry. This method combines the use of a pressurised fluid with a triple quadrupole MS/MS system, resulting in benefits from both systems: high extraction efficiency and sensitivity. The effects of solvent type and PLE operational parameters, such as temperature and extraction time, were studied to obtain maximum recovery of the analytes with minimum contamination. HA extraction was best achieved using dichloromethane/acetone (50/50, v/v) at 80 °C for 10 min. Recoveries ranged from 45% to 79% with good quality parameters: limit of detection values between 0.02 and 1 ng g −1, linearity ( r 2 > 0.997), and run-to-run and day-to-day precisions with relative standard deviations lower than 13% achieved at both low (0.20 μg g −1) and medium (1.0 μg g −1) concentrations. This method reduces sample manipulation and total extraction time by nearly four-fold compared to conventional solid phase extraction. The optimised method was validated using laboratory reference material based on a meat extract, and was successfully applied to HA analysis in several cooked beef samples.

Immersion vacuum cooling of cooked beef – Safety and process considerations regarding beef joint size

Cooked beef samples (1, 2, and 3 kg; 4.7, 5.6, and 6.2 cm average radius, respectively) were cooled from ∼72 to 4 °C core temperature using either air blast (AB), immersion vacuum (IVC) or vacuum (VC) cooling. IVC cooled larger samples within 4 h and took less than 2.5 h between 72 and 10 °C. IVC cooling times were on average shorter than AB and longer than VC for all sizes. Differences increased with size. IVC and AB cooling losses were comparable ( P > 0.05) while lower on average ( P < 0.05) than VC losses for same size samples. Additionally, samples between 1.0 and 4.3 kg (4.2–8.7 cm average radius) were cooled by either IVC or VC. Cooling times were between 2.8 and 5.5 h for IVC and between 1.1 and 3.2 h for VC. There was a significant effect ( P < 0.01) of sample size on IVC cooling times. Cooling profiles of larger samples were tested using USDA cooling growth model for Clostridium perfringens in beef broth. According to the model, none of the analyzed profiles would support significant growth of the bacteria.

한우수소의 부위별 영양성분조성 및 이화학적 육질특성

본 연구는 일반적으로 낮은 육질등급으로 유통되는 한우수소고기에 대하여 소비자 관능평가를 실시하여 사회인구학적 요인과 한국소비자들의 관능특성간에 어떠한 관계가 있는지 알아보고, 이 결과를 한국소비자들을 위한 요리방법별 부위별 맛 예측 모델을 설정하기 위한 기초자료로 활용하고자 수행하였다. 24개월령 한우수소를 도축한 후 업진, 보섭, 채끝, 등심, 꾸리, 홍두깨, 목심, 설깃, 우둔, 양지부위를 분리하여 전국 소비자 650명을 대상으로 탕, 그릴 및 구이형태로 각각 조리하여 연도, 다즙성, 향미 및 전반적인 기호도를 평가한 결과 탕형태로 조리된 한우수소고기는 거주지역, 연령, 성별, 직업, 고기섭취습관 및 10개의 부위에 대한 관능특성 4가지 요인(연도, 다즙성, 향미 및 전반적인 기호도)과 모두 관련이 있는 것으로 나타났다. 스테이크 형태인 경우 쇠고기에 대한 기호성향이 거주지역, 연령 및 식습관 등과 유의적인 차이가 없는 것으로 나타났으나 직업, 가족수, 가계수입 및 부위에 따라서는 유의적인 차이가 있는 것으로 나타났다(p<0.01). 구이형태인 경우 거주지역, 연령, 직업, 가계수입, 식습관 및 부위에 따라 기호도 성향에 차이가 있었다. 또한, 한우수소고기의 관능평가 결과에 대하여 주성분 분석을 실시한 결과 요리방법에 따라 연도, 다즙성, 향미 및 기호도가 부위별 관능특성에 미치는 가중치가 다른 것으로 분석되었다. 결론적으로 한국소비자들은 동일한 조건의 쇠고기일지라도 요리방법 및 부위에 따라 쇠고기 맛을 평가하는 기호도에 차이가 있었으며 이러한 점을 고려하여 부위별요리방법별 맛 예측모델을 확립한다면 한우고기를 차별화할 수 있는 유통시스템 개발이 가능할 것으로 생각된다. This study was conducted to investigate the relationship between the socio-demographic factors and the Korean consumers’ palatability evaluation and to collect the sensory information for development of prediction palatability model of Hanwoo beef. Ten cuts〔Abjin (short plate), Bosup (top sirloin), Cheggt (striploin), Dngsim (loin), Guri (chuck tender), Hongduke (eye of round), Moksim (chuck roll), Sulgit (bottom round), Udoon (top round), Yangi (brisket)〕 were separated from 10 Hanwoo bulls beef(～24 months old) and prepared with the same manner for 3 different cooking methods such as boiling, grilling and roasting. The cooked beef samples were served to 650 consumers recruited from Seoul, Joongbu, Honam and Youngnam locations and evaluated tenderness, juiciness, flavor and overall acceptability. The living location, age, gender, occupation, eating habit and cut were significantly related with the sensory properties when bull beef were cooked as boiled cooking(p<0.05). In grill cooking, only occupation, income and cut had the significant effect on the overall acceptability of Hanwoo bull beef(p<0.01). When bull beef were cooked as Korean traditional roast cooking, consumer’s sensory properties were significantly different by the living location, age, occupation, income, eating habit of consumers and cut(p<0.05). Also, results from the principal component analysis showed that palatability scores of Korean consumers were decided with different contribution scores of tenderness, juiciness, flavor and overall acceptability of cut depending on cooking methods. In conclusion, Korean consumers’ palatability for Hanwoo bull beef were related with the socio-demographic factors and the sensory results were different by cut and cooking methods.

사회인구학적 요인이 한우수소고기의 부위 및 요리형태별 관능특성에 미치는 영향

본 연구는 일반적으로 낮은 육질등급으로 유통되는 한우수소고기에 대하여 소비자 관능평가를 실시하여 사회인구학적 요인과 한국소비자들의 관능특성간에 어떠한 관계가 있는지 알아보고, 이 결과를 한국소비자들을 위한 요리방법별 부위별 맛 예측 모델을 설정하기 위한 기초자료로 활용하고자 수행하였다. 24개월령 한우수소를 도축한 후 업진, 보섭, 채끝, 등심, 꾸리, 홍두깨, 목심, 설깃, 우둔, 양지부위를 분리하여 전국 소비자 650명을 대상으로 탕, 그릴 및 구이형태로 각각 조리하여 연도, 다즙성, 향미 및 전반적인 기호도를 평가한 결과 탕형태로 조리된 한우수소고기는 거주지역, 연령, 성별, 직업, 고기섭취습관 및 10개의 부위에 대한 관능특성 4가지 요인(연도, 다즙성, 향미 및 전반적인 기호도)과 모두 관련이 있는 것으로 나타났다. 스테이크 형태인 경우 쇠고기에 대한 기호성향이 거주지역, 연령 및 식습관 등과 유의적인 차이가 없는 것으로 나타났으나 직업, 가족수, 가계수입 및 부위에 따라서는 유의적인 차이가 있는 것으로 나타났다(p<0.01). 구이형태인 경우 거주지역, 연령, 직업, 가계수입, 식습관 및 부위에 따라 기호도 성향에 차이가 있었다. 또한, 한우수소고기의 관능평가 결과에 대하여 주성분 분석을 실시한 결과 요리방법에 따라 연도, 다즙성, 향미 및 기호도가 부위별 관능특성에 미치는 가중치가 다른 것으로 분석되었다. 결론적으로 한국소비자들은 동일한 조건의 쇠고기일지라도 요리방법 및 부위에 따라 쇠고기 맛을 평가하는 기호도에 차이가 있었으며 이러한 점을 고려하여 부위별요리방법별 맛 예측모델을 확립한다면 한우고기를 차별화할 수 있는 유통시스템 개발이 가능할 것으로 생각된다. This study was conducted to investigate the relationship between the socio-demographic factors and the Korean consumers’ palatability evaluation and to collect the sensory information for development of prediction palatability model of Hanwoo beef. Ten cuts〔Abjin (short plate), Bosup (top sirloin), Cheggt (striploin), Dngsim (loin), Guri (chuck tender), Hongduke (eye of round), Moksim (chuck roll), Sulgit (bottom round), Udoon (top round), Yangi (brisket)〕 were separated from 10 Hanwoo bulls beef(～24 months old) and prepared with the same manner for 3 different cooking methods such as boiling, grilling and roasting. The cooked beef samples were served to 650 consumers recruited from Seoul, Joongbu, Honam and Youngnam locations and evaluated tenderness, juiciness, flavor and overall acceptability. The living location, age, gender, occupation, eating habit and cut were significantly related with the sensory properties when bull beef were cooked as boiled cooking(p<0.05). In grill cooking, only occupation, income and cut had the significant effect on the overall acceptability of Hanwoo bull beef(p<0.01). When bull beef were cooked as Korean traditional roast cooking, consumer’s sensory properties were significantly different by the living location, age, occupation, income, eating habit of consumers and cut(p<0.05). Also, results from the principal component analysis showed that palatability scores of Korean consumers were decided with different contribution scores of tenderness, juiciness, flavor and overall acceptability of cut depending on cooking methods. In conclusion, Korean consumers’ palatability for Hanwoo bull beef were related with the socio-demographic factors and the sensory results were different by cut and cooking methods.

Evaluation of Milk Mineral Antioxidant Activity in Beef Meatballs and Nitrite-cured Sausage

: The objective of this study was to determine the antioxidant activity of 1.5% milk mineral (MM) added to uncured cooked beef meatballs and to evaluate possible synergistic effects of MM in combination with 20-ppm or 40-ppm sodium nitrite in beef sausages. All treatments were also formulated with 1.5% salt and 10% added water. Thiobarbituric acid (TBA) values and Hunter color values were determined at 1 d, 8 d, and 15 d of storage at 2°C. Meatball cooked yield was also measured. Cooked yield was not different (P < 0.05) between control meatballs and those containing MM. As expected, treatments containing nitrite had higher redness (CIE a*) than samples without nitrite. Redness values increased with storage time in sausages containing 40-ppm nitrite. However, redness values decreased (P < 0.05) during storage for control meatballs, associated with increased lipid oxidation (higher TBA values). Lipid oxidation was lower (P < 0.05) in samples containing 1.5% MM with TBA values <1.2 after 15 d of storage compared with 6.1 for control samples. There was no synergistic inhibition of lipid oxidation in samples containing 20-ppm or 40-ppm sodium nitrite plus 1.5% MM. Milk mineral alone at 1.5% of meat weight was sufficient for inhibition of lipid oxidation in cooked beef samples.