Relative contribution of sensory characteristics for different types of pork loin, assessed by temporal dominance of sensations.

BACKGROUND: Sensory perception is a dynamic process occurring sequentially. The dynamic analysis of the perception of sensory characteristics in meat is important to understand complex meat sensory characteristics. Temporal dominance of sensations (TDS) is a dynamic sensory method that captures the 'dominance of sensations' throughout food consumption, and it is possible to calculate the relative contribution of various sensory characteristics by 'dominance rate' over time. The objective of this study was to assess the major sensory characteristics of the dynamic sensory perception of pork loin. Using the TDS, we evaluated pork loins derived from pigs with different genetic and feeding backgrounds. Moreover, we checked the integrity of the TDS by comparing the TDS results with a descriptive sensory analysis and a physico-chemical analysis. RESULTS: Seven types of pork loin were evaluated by TDS, and 'tender and/or soft,' 'tough and/or hard,' 'juicy,' 'dry,' 'fat melting,' 'smoothness,' 'sourness,' 'umami,' and 'beast odors' became dominant in at least one type of pork loin. The dynamics of the perception of pork sensory characteristics was also depicted by TDS. In addition, TDS and descriptive analysis demonstrated similarity in principal component analysis. CONCLUSION: TDS demonstrated the major sensory characteristics on the dynamic sensory perception of pork loin. © 2019 Society of Chemical Industry.

Relationship between water-holding capacity and intramuscular fat content in Japanese commercial pork loin.

OBJECTIVE: The relationship between water-holding capacity (WHC) and intermuscular fat (IMF) was studied in Japanese commercial pork. METHODS: Longissimus muscles of pigs (n = 62), obtained from two meat packing plants, were analyzed for IMF content, moisture content, drip loss, cooking loss, and pH. Pairwise relationships among these traits were determined using correlation analyses. RESULTS: IMF content was significantly correlated with moisture content (r = -0.88; p<0.01) and pH (r = 0.32; p<0.05), but not with drip loss (r = -0.23; p = 0.07) or cooking loss (r = -0.10; p = 0.42). In contrast, drip loss was significantly (and negatively) correlated with pH (r = -0.57; p<0.01). CONCLUSION: IMF content was not significantly correlated with WHC in pork, and so ultimately, we consider pH to be one of the most important factors influencing WHC in pork meat.

Classification and characterization of Japanese consumers' beef preferences by external preference mapping.

BACKGROUND: Over the past few decades, beef producers in Japan have improved marbling in their beef products. It was recently reported that marbling is not well correlated with palatability as rated by Japanese consumers. This study sought to identify the consumer segments in Japan that prefer sensory characteristics of beef other than high marbling. RESULTS: Three Wagyu beef, one Holstein beef and two lean imported beef longissimus samples were subjected to a descriptive sensory test, physicochemical analysis and a consumer (n = 307) preference test. According to consumer classification and external preference mapping, four consumer segments were identified as 'gradual high-fat likers', 'moderate-fat and distinctive taste likers', 'Wagyu likers' and 'distinctive texture likers'. Although the major trend of Japanese consumers' beef preference was 'marbling liking', 16.9% of the consumers preferred beef samples that had moderate marbling and distinctive taste. The consumers' attitudes expressed in a questionnaire survey were in good agreement with the preference for marbling among the 'moderate-fat and distinctive taste likers'. CONCLUSION: These results indicate that moderately marbled beef is a potent category in the Japanese beef market. © 2017 Society of Chemical Industry.

Effects of Cooking End-point Temperature and Muscle Part on Sensory 'Hardness' and 'Chewiness' Assessed Using Scales Presented in ISO11036:1994.

Texture and 'tenderness' in particular, is an important sensory characteristic for consumers' satisfaction of beef. Objective and detailed sensory measurements of beef texture have been needed for the evaluation and management of beef quality. This study aimed to apply the sensory scales defined in ISO11036:1994 to evaluate the texture of beef. Longissimus and Semitendinosus muscles of three Holstein steers cooked to end-point temperatures of 60°C and 72°C were subjected to sensory analyses by a sensory panel with expertise regarding the ISO11036 scales. For the sensory analysis, standard scales of 'chewiness' (9-points) and 'hardness' (7-points) were presented to the sensory panel with reference materials defined in ISO11036. As a result, both 'chewiness' and 'hardness' assessed according to the ISO11036 scales increased by increasing the cooking end-point temperature, and were different between Longissimus and Semitendinosus muscles. The sensory results were in good agreement with instrumental texture measurements. However, both texture ratings in this study were in a narrower range than the full ISO scales. For beef texture, ISO11036 scales for 'chewiness' and 'hardness' are useful for basic studies, but some alterations are needed for practical evaluation of muscle foods.

Radiocesium distribution in the tissues of Japanese Black beef heifers fed fallout-contaminated roughage due to the Fukushima Daiichi Nuclear Power Station accident.

This study examined the accumulation and tissue distribution of radioactive cesium nuclides in Japanese Black beef heifers raised on roughage contaminated with radioactive fallout due to the accident at the Fukushima Daiichi Nuclear Power Station on March 2011. Radiocesium feeding increased both (134)Cs and (137)Cs levels in all tissues tested. The kidney had the highest level and subcutaneous adipose had the lowest of radioactive cesium in the tissues. Different radioactive cesium levels were not found among parts of the muscles. These results indicate that radiocesium accumulated highly in the kidney and homogenously in the skeletal muscles in the heifers.

Meat consumption and consumer attitudes in Japan: An overview.

Among Asian countries, Japan has the shortest history of eating meat in its food culture. It was only after 2007 that household fresh meat consumption surpassed fresh fish consumption in Japan. Although it was forecast that slowing population and economic growth would limit the demand for meat, household meat consumption in 2020 increased remarkably from that in 2019, perhaps due to COVID-19. Meat consumption has regional variations within Japan attributable to historical background. Japanese consumers prefer domestically produced meat and focus on the visual characteristics of meat, in particular marbling. Extrinsic factors such as information also contribute to Japanese consumers' meat choices more than the quality of the meat. Although Japanese consumers are concerned about the safety of meat, reassurance from appropriate inspection will restore their purchasing intention. Novel factors such as animal welfare and environment-friendly production are also recognized in Japan. Also notable is that wild animal meat consumption is beginning to increase in recent years.

Estimation of discrimination threshold for emulsified chicken oil in chicken broth.

Although fat content affects the texture and flavor of meat and meat products, the fat discrimination thresholds are unknown. This study aimed to elucidate the discrimination threshold of fat in meat products using broth from chicken thigh meat as a meat taste model. In Experiment 1, triangle tests were conducted between 1%, 0.2%, 0.04%, and 0.008% (w/v) chicken oil-supplemented broth and broth without chicken oil. The results indicated the discrimination threshold to be between 0.04% and 0.008% (w/v). In Experiment 2, similar triangle tests were conducted using oil supplementation at 0.1%, 0.0333%, 0.0111%, and 0.0037% to refine the discrimination threshold. Logistic regression analysis revealed that the discrimination threshold of emulsified chicken oil in chicken broth was 0.0387% (w/v). We demonstrated that chicken oil made a sensory difference in chicken broth at a low concentration and indicates that the chicken oil strongly affects the sensory characteristics of chicken broth.

Changes in thiamin contents in porcine muscles and liver during growth.

Changes in the thiamin contents in three types of porcine muscle and porcine liver during growth were investigated. The muscular thiamin content was lower at the newborn stage than at fetal stage, and increased after the weaning period. The liver thiamin content, however, remained unchanged from the fetal stage to 5 months old. The changes in thiamin contents were different between Landrace and Meishan pigs.

Assessment of the dynamics of sensory perception of Wagyu beef strip loin prepared with different cooking methods and fattening periods using the temporal dominance of sensations.

In this study, we assessed the relative sensory perception of Wagyu beef using temporal dominance of sensations (TDS), which is a dynamic sensory method that captures the "dominance of sensation" throughout food consumption. In addition, we checked the integrity of the TDS by comparing the TDS results with a physicochemical analysis. Strip loins were obtained from 24- and 28-month-old Japanese Black cattle ("Wagyu") and were cooked by grilling (yakiniku) or boiling (shabu-shabu). Temporal dominance of sensations was then used to evaluate the four types of samples. "Tender and/or soft," "juicy," "dry," "fat melting," "fat taste," "umami," "sweet taste," and "butter odor" were dominant in at least one of the sample types, with the yakiniku cooking method highlighting texture- and fat-related sensory characteristics, and the shabu-shabu cooking method highlighting flavor-related sensory characteristics. In addition, beef obtained from the 24-month-old Wagyu was significantly more "dry" than that of the 28-month-old cattle, reflecting their different cooking loss. Temporal dominance of sensations successfully demonstrated the dominant sensory perceptions of Wagyu beef prepared with different cooking methods and fattening periods.

Descriptive Sensory Traits of Cooked Eggs Laid from Hens Fed Rice Grain.

Descriptive sensory characteristics of eggs produced by conventional corn-based feeding and unhulled whole rice grain-feeding were compared in two cooking procedures using a trained panel. Rice-feeding significantly decreased brothy and roasted odor in eggs cooked into half-cooked egg yolks, and decreased the creamy odor, smoothness and moisture of eggs cooked into custard puddings. However, a statistical interaction between rice-feeding and production farm was not observed in every sensory attribute. These findings indicated that replacing corn with unhulled whole rice grain in diets for laying hens alters the sensory attributes of eggs.

In situ characterization of acidic and thermal protein denaturation by infrared microspectroscopy.

Foods meet acid pH during gastric digestion after cooking. An in situ infrared microspectroscopy approach was developed to detect the effects of heat and acid treatments on protein structure separately. Infrared spectra were obtained from meat samples treated with heat and/or acid, and wavenumbers accounting independently for the treatments were extracted by principal component regression. Extreme-acid treatment (pHinitial 2.0) was well predicted (0.5% error) by a simple ratio of as-observed spectral intensities at 1211 and 1396 cm-1, reflecting a perturbation in the vibration of amino acid residues (phenylalanine, tyrosine and aspartic acid) by protein unfolding and protonation. Using the imaging mode of an IR microscope, meat protein acidification was evidenced with high spatial resolution. The heat effect was well discriminated from the acid effect by the ratio of as-observed intensities at 1666 and 1697 cm-1 (0.9% error), indicating content of aggregated ß-sheets relative to α-helix structure.

Changes in the amounts of water-soluble umami-related substances in porcine longissimus and biceps femoris muscles during moist heat cooking.

Time course changes in amounts of glutamic acid, total free amino acid, inosine monophosphate (IMP), and 2%-trichloroacetic acid-soluble oligopeptides in whole, muscle only, and cooking juice during wet-heat cooking in pork longissimus and biceps femoris muscles were investigated because the movements of umami-relevant substances during cooking treatment had not previously been clarified in detail. The amounts of glutamic acid, total free amino acid, and IMP significantly (P<.05) decreased and increased in muscle and cooking juice during 180min of cooking, respectively. The whole amounts of glutamic acid and total free amino acid remained unchanged during cooking treatment. The whole amount of IMP, however, increased significantly at 10min of cooking (P<.05) and was maintained after the 10-min period. The extramuscular oligopeptides amount increased significantly in response to the cooking treatment (P<.05). The intramuscular amount of oligopeptides decreased at 30min of cooking but increased significantly (P<.05) after 60min. The whole meat oligopeptides amount increased significantly during a 180-min cooking treatment (P<.05). These results indicate that glutamate, total free amino acid, and IMP were released from the muscle during cooking, and that IMP levels increased in the initial phase of cooking. In addition, oligopeptides increased during wet-heat cooking of pork muscles.

Qualitative and Quantitative Comparisons of Texture Characteristics between Broiler and Jidori-niku, Japanese Indigenous Chicken Meat, Assessed by a Trained Panel.

The texture of jidori-niku (Japanese indigenous native chicken meat) was characterized and compared with those of Chunky broiler chicken meat. Experiment 1: A qualitative sensory test using jidori-niku and broiler breast (pectoralis major, PM), thigh (biceps femoris, BF) and sasami (deep pectoral) meat cooked to the end-point temperature 75°C by steam-heating was administered to a trained sensory panel (n=16-17) for the selection of descriptive texture items from ISO5492 texture words. By the correspondence analysis, the characteristics of 'chewiness,' 'hardness' and 'springiness' were found to be different between jidori-niku and broiler: they likely characterize jidori-niku texture. Experiment 2: Texture characteristics in the three above-mentioned muscles in jidori-niku and broiler were compared quantitatively using the three above-mentioned texture items by the trained sensory panel. Sensory chewiness and hardness were the highest in the broiler PM and second highest in the jidori-niku BF, whereas sensory springiness was the highest in the jidori-niku BF. These results suggest that jidori-niku-like texture was characterized as a springy texture as compared to broiler meat.

Simultaneous imaging of fat crystallinity and crystal polymorphic types by Raman microspectroscopy.

The crystalline states of fats, i.e., the crystallinity and crystal polymorphic types, strongly influence their physical properties in fat-based foods. Imaging of fat crystalline states has thus been a subject of abiding interest, but conventional techniques cannot image crystallinity and polymorphic types all at once. This article demonstrates a new technique using Raman microspectroscopy for simultaneously imaging the crystallinity and polymorphic types of fats. The crystallinity and ß' crystal polymorph, which contribute to the hardness of fat-based food products, were quantitatively visualized in a model fat (porcine adipose tissue) by analyzing several key Raman bands. The emergence of the ß crystal polymorph, which generally results in food product deterioration, was successfully imaged by analyzing the whole fingerprint regions of Raman spectra using multivariate curve resolution alternating least squares analysis. The results demonstrate that the crystalline states of fats can be nondestructively visualized and analyzed at the molecular level, in situ, without laborious sample pretreatments.

Genomic structural analysis of porcine fatty acid desaturase cluster on chromosome 2.

Fatty acid composition is an economically important trait in meat-producing livestock. To gain insight into the molecular genetics of fatty acid desaturase (FADS) genes in pigs, we investigated the genomic structure of the porcine FADS gene family on chromosome 2. We also examined the tissue distribution of FADS gene expression. The genomic structure of FADS family in mammals consists of three isoforms FADS1, FADS2 and FADS3. However, porcine FADS cluster in the latest pig genome assembly (Sscrofa 10.2) containing some gaps is distinct from that in other mammals. We therefore sought to determine the genomic structure, including the FADS cluster in a 200-kbp range by sequencing gap regions. The structure we obtained was similar to that in other mammals. We then investigated the porcine FADS1 transcription start site and identified a novel isoform named FADS1b. Phylogenetic analysis revealed that the three members of the FADS cluster were orthologous among mammals, whereas the various FADS1 isoforms identified in pigs, mice and cattle might be attributable to species-specific transcriptional regulation with alternative promoters. Porcine FADS1b and FADS3 isoforms were predominantly expressed in the inner layer of the subcutaneous adipose tissue. Additional analyses will reveal the effects of these functionally unknown isoforms on fatty acid composition in pig fat tissues.

Characterization and classification of Japanese consumer perceptions for beef tenderness using descriptive texture characteristics assessed by a trained sensory panel.

Meat tenderness is an important characteristic in terms of consumer preference and satisfaction. However, each consumer may have his/her own criteria to judge meat tenderness, because consumers are neither selected nor trained like an expert sensory panel. This study aimed to characterize consumer tenderness using descriptive texture profiles such as chewiness and hardness assessed by a trained panel. Longissimus muscles cooked at four different end-point temperatures were subjected to a trained sensory panel (n=18) and consumer (n=107) tenderness tests. Multiple regression analysis showed that consumer tenderness was characterized as 'low-chewiness and low hardness texture.' Subsequently, consumers were divided into two groups by cluster analysis according to tenderness perceptions in each participant, and the two groups were characterized as 'tenderness is mainly low-chewiness' and 'tenderness is mainly low-hardness' for tenderness perception, respectively. These results demonstrate objective characteristics and variability of consumer meat tenderness, and provide new information regarding the evaluation and management of meat tenderness for meat manufacturers.

In situ Raman spectrometric analysis of crystallinity and crystal polymorphism of fat in porcine adipose tissue.

From the adipose tissues of pork carcasses stored in a refrigerator, Raman spectra were observed in situ by a portable Raman spectrometer. The observed Raman spectra, which were almost completely due to fat, showed clear dependence on the refrigeration time and carcass temperature. This dependence reflected an increase in the crystallinity of the fat and a change in the fraction of the ß' polymorph. Evidence of changes in the packing order of the aliphatic chains of acylglycerol molecules was obtained, and the changes lasted for a long time after the temperature reached the lowest point (4.3 °C). Possibilities of using Raman spectrometry as a tool for routine monitoring of the conditions of carcasses as well as for research on the improvement of the mechanical strength of the adipose tissue are discussed.

Increased intramuscular fat improves both 'chewiness' and 'hardness' as defined in ISO5492:1992 of beef Longissimus muscle of Holstein × Japanese black F1 steers.

It is considered that high-fat beef is more 'tender' than low-fat beef in Japanese consumers. However, 'tenderness' which has been an important beef characteristic, has not been commonly defined. ISO5492:1992 provides internationally established items for sensory texture analysis with simple definitions, and the items classified under 'chewiness' and 'hardness' as defined in the international standard are characterized as useful texture descriptors for beef. The aim of this study was to investigate the effects of intramuscular fat on beef texture using the ISO5492 texture vocabulary. Longissimus muscles were harvested from Holstein × Japanese black F1 beef steers with different intramuscular fat levels and were subjected to sensory tests by a trained panel using ISO5492:1992 texture terms. Correspondence analysis indicated that the intramuscular fat level was related to both 'chewiness' and 'hardness' and the intensities of these characteristics decreased as intramuscular fat increased. These findings suggest that intramuscular fat improves both 'chewiness' and 'hardness' as defined in ISO5492:1992.

Impressions and purchasing intentions of Japanese consumers regarding pork produced by 'Ecofeed,' a trademark of food-waste or food co-product animal feed certified by the Japanese government.

Impressions and purchasing intentions of Japanese consumers regarding pork produced by 'Ecofeed', a trademark of food-waste or co-product animal feeds certified by the Japanese government, were investigated by a questionnaire on the Internet. 'Ecofeed' did not elicit specific impressions as compared to domestic, imported, Kurobuta (in Japan), and specific pathogen-free (SPF) pork. Purchasing intent for 'Ecofeed' pork was the second lowest of the five pork products. Knowledge and purchasing experience regarding 'Ecofeed' pork was the lowest of the five pork products. Respondents were classified into four categories according to their impressions of 'Ecofeed' pork. The largest category of respondents did not have any specific impression of 'Ecofeed' pork and had little knowledge of pork farming. A category that had a positive impression for 'Ecofeed' pork had high knowledge of the pork farming system. In order to establish 'Ecofeed' pork in Japan, our results suggest that information disclosure and education about 'Ecofeed', its certification system, environmental benefits and the current self-efficiency ratio of animal feed, are needed.