Effect of visual marbling on sensory properties and quality traits of pork loin

Pork loins (N = 53) were selected from a commercial packing plant to determine the influence of subjective marbling score on sensory attributes and eating quality properties. The pork loins were obtained from commercially raised hybrid barrows (average carcass weight = 67.7 kg), originating from nine cooperating herds, and fed similar diets throughout the finishing period. Carcass quality measurements, trained sensory panel analyses, fatty acid composition, thiobarbituric acid-reactive substance (TBARS) index, and cholesterol content were assessed and analyzed on the individual pork loins. With an increase in marbling level, there was a corresponding decrease in drip loss (P = 0.049) and observed increases in pH (P = 0.001), sensory tenderness (P = 0.001), and sensory juiciness scores (P = 0.017). The most notable results demonstrated that protein concentrations were reduced as marbling levels amplified (P = 0.012). The increase in marbling score was observed to be a significant source of variation in polyunsaturated fatty acid (PUFA) concentrations. Linoleic and arachidonic acids decreased in both raw and cooked samples as marbling score increased. The data demonstrated that visual marbling score does have an influence on sensory properties and pork quality.     

Cooking method and endpoint temperature effects on sensory and color characteristics of pumped pork loin chops

The objective of this study was to evaluate the effects of pumping, cooking method and endpoint temperature on quality of fresh pork chops. The longissimus was removed from 30 paired pork sides. One side was pumped to 110% of original weight (0.4% phosphate, 0.4% salt+added water). Chops were cut (2.5 cm thick) then fried or grilled to 70 or 80 °C. As endpoint temperature increased from 70 to 80 °C, pork flavor increased (P<0.05) from 95 to 104 (on a 150 point scale) for pumped samples but remained constant in unpumped samples. Juiciness decreased when unpumped samples cooked to 80 °C (62) rather than 70 °C (78). Warner–Bratzler shear values were lower (P<0.05) in pumped chops than in unpumped controls. Pork flavor was higher and off-flavor was lower in fried chops. Pumping loins appears to enhance sensory attributes of chops even when cooked to abusive endpoint temperatures with limited detrimental effects on physical characteristics.     

Effect of tumbling and RN genotype on sensory perception of cured-smoked pork loin

Effects of tumbling and RN genotype on sensory perception of cured-smoked loins were studied on loins from 32 crossbred female pigs containing Hampshire blood. Right-side loins were intermittently tumbled during 4 h, whereas left-side loins were left non-tumbled. Tumbled loins were more tender and uniform in cured colour as well as less acidulous in taste compared with non-tumbled loins. Further, the formation of undesirable pores was lower in tumbled loins. Final juiciness tended to be higher and meat taste intensity lower in tumbled loins, whereas initial juiciness did not differ. There were no significant interactions between tumbling and RN genotype for sensory attributes. RN⁻ carriers (RN⁻/rn⁺) were more acidulous in taste, had more pronounced meat taste and were saltier than non-carriers (rn⁺ /rn⁺). Moreover, they tended to have higher initial juiciness and more undesirable pores, and be less homogeneous in cured pink colour. No differences in consumer preference between the four treatments were detected in the ranking test, but most persons ranked non-tumbled loins highest regarding overall liking. Instrumental tenderness measurements agreed well with sensory tenderness scores.     

Effects of muscle cortisol concentration on muscle fiber characteristics, pork quality, and sensory quality of cooked pork

The effect of muscle cortisol concentration on muscle fiber characteristics and technological and sensory quality of pork was investigated. With the exception of the percentage of type IIA fibers, muscle fiber characteristics were not associated to cortisol levels. However, muscle cortisol concentration was positively associated with muscle pH(24h) (r = 0.23, P<0.05) and negatively associated with drip loss (r = -0.49, P<0.001), lightness (r = -0.24, P<0.05), shear force (r = -0.25, P<0.05), and texture profile analysis-hardness (r = -0.35, P<0.01). Additionally, the water-holding capacity of meat samples was affected by cortisol levels, with lower cortisol concentrations associated with less tender samples. These results indicate that the concentration of cortisol in the muscle is related with meat quality as well as the sensory quality of cooked pork.     

Correlations of trained panel sensory values of cooked pork with fatty acid composition,muscle fiber type,and pork quality characteristics in Berkshire pigs

The objective was to examine the relationship of trained panel sensory scores of cooked pork with fatty acid composition, muscle fiber type, and meat quality characteristics from Berkshire pigs. No or few associations were found between the panel sensory scores of cooked meat, especially tenderness attributes, and fatty acid composition; however, intramuscular fat content positively correlated with off-flavor score (r = 0.31). On the other hand, the morphological characteristics of muscle fibers were correlated with panel sensory values. Muscles with smaller cross-sectional area and higher density of fibers were more closely associated with softer, more tender panel scores and a lower number of chews than muscles with larger fiber area and lower density of fibers. The water holding capacity test of filter-paper fluid uptake was moderately correlated with panel scores of softness (r = 0.33), initial tenderness (r = 0.38), chewiness (r = 0.40), juiciness (r = − 0.27), flavor intensity (r = − 0.23), and off-flavor (r = 0.30). Panel sensory values of Berkshire pig meat was moderately related to postmortem meat quality, especially water holding capacity. A more thorough understanding of the relationships between fatty acid composition and muscle fiber type with palatability is needed.     

Marbling effects on quality characteristics of pork loin chops: consumer purchase intent, visual and sensory characteristics

These studies evaluated whether consumers detect differences among pork loin chops with low (1.05% fat), medium (2.33%) and high (3.46%) amounts of marbling when visually evaluated, when prepared under controlled conditions, and when prepared at home. Highly marbled chops appeared lighter colored, less lean, had less acceptable appearance, and were less likely to be purchased than leaner chops; they were juicier, more tender, oily and flavorful than leaner chops. These results indicate a disparity between purchase intent based on visual evaluation, and quality attributes of the cooked product. When evaluated at home, consumers rated the chops they chose (40% low, 40% medium marbled) as more tender, juicy and flavorful than chops they evaluated "blind" on-site suggesting that additional factors have a significant impact on stated purchase intent.     

Enhancing pork loin quality attributes through genotype,chilling method and ageing time

The experiment was conducted to examine opportunities for enhancing pork quality through the use of post-mortem ageing when combined with different chilling regimes. Large White (LW, n = 24) and Duroc × Large White (Duroc, n = 24) barrows were slaughtered and alternate carcass sides were either conventionally or blast-chilled. The longissimus thoracis et lumborum muscle was dissected from the carcass sides (24 h post-mortem) and trimmed of cover fat. Three sections (15 cm length) were vacuum packaged and assigned to 2, 7 or 14 days of ageing (2 °C) randomized within muscle location. Blast-chilled meat had lower purge (P = 0.009) and drip (P = 0.0009) losses and higher hue (P = 0.02) than conventionally chilled meat. However chilling by conventional or blast-chilling methods had no effect on sensory characteristics (P > 0.1). When breeds were compared, meat from Duroc barrows had lower moisture (P < 0.0001) and higher intramuscular fat content (P < 0.0001), L∗ (P = 0.0003) and hue (P = 0.007) values than LW. Overall tenderness (P = 0.005), juiciness (P = 0.0007) and palatability (P < 0.0001), as well as flavour intensity (P < 0.0001) and desirability (P < 0.0001) values were higher and undesirable flavours were lower (P < 0.0001) for meat from Duroc pigs, when compared with LW. Ageing increased purge loss (P < 0.0001), L∗ (P < 0.0001), hue (P < 0.0001), chroma (P < 0.0001) and content of protein (P = 0.002), with corresponding decreases (P < 0.0001) in drip loss and moisture content. Instrumental (P < 0.0001) and sensory (initial, P < 0.0001 and overall, P < 0.0001) tenderness increased from day 2 to 14. Therefore independent of chilling method, ageing improved quality of pork loins. Moreover ageing had greater effect on tenderness, while breed had greater effect on flavour which may be related to differences in intramuscular fat content.     

Texture,sensory and swallowing characteristics of high-pressure-heat-treated pork meat gel as a dysphagia diet

To develop a soft meat product for a dysphagia diet, high-pressure technology was applied. Pressure-heat-treated ground pork meat (PH) was prepared from ground pork mixed with water (ground meat: water, 1:0.5 or 1:1) and salt (1.5%). PH-gels were made from these meat homogenates by treatment at 400 MPa for 20 min, followed by heat treatment. Heat-treated pork meat homogenates (H) were also prepared. The hardness and adhesiveness of the 1:1PH-gel was lower than those of the 1:1H-gel. The PH-gel scored higher in sensory evaluations of elasticity, smoothness and ease of swallowing. Scanning electron micrographs indicated that the superior textural property of the 1:1PH-gel was caused by a network of myosin filaments. Videofluoroscopic examination of swallowing revealed that the 1:1PH-gel was easy to swallow and left little residue in the oropharynx. These results proved the utility of pressurization in creating a dysphagia meat diet.     

粳米品质特性及与感官质量关系研究

为明确东北地区不同品种粳米品质差异,找出影响感官质量的关键因素,以稻花香二号、盐丰和辽星大米为研究对象,对其外观特性、理化性质、质构特性、蒸煮特性、香气和感官评价进行分析。结果表明:L^*、a^*、b^*、弹性、黏着性、咀嚼性、吸水率、pH值没有显著性差异(P>0.05),含水量、蛋白质含量、脂肪含量、脂肪酸值、巯基含量、硬度、回复性和膨胀性则差异显著(P<0.05)。电子鼻判别因子分析对3种大米区分明显。GC-MS共鉴定出53种化合物,其中稻花香二号、盐丰和辽星中分别检测到38、28、28种香气成分,有15种物质在3种大米中同时出现,OAV法进一步得到壬醛、癸醛等7种香气活性物质。感官评价综合分值从高到低依次为稻花香二号、辽星和盐丰,其中脂肪含量和脂肪酸值与感官综合评分呈显著负相关,巯基含量、硬度和黏着性与感官综合评分呈显著正相关。     

Microbiological and sensory characteristics of pork loin chops: Role of subcutaneous fat

Pork loin chops with the subcutaneous fat attached, without subcutaneous fat and the subcutaneous fat that was removed from chops were packaged and stored at 4°C±1°C in polyvinyl chloride (PVC) film for 0-6 days or in high-oxygen barrier (HOB) film for 0-28 days. Aerobic plate counts (APCs) of lean and fat of intact chops packaged and stored in either PVC or HOB film did not differ (P>0·05) in most comparisons. The APCs of subcutaneous fat portions that were packaged and stored separately in HOB film often were higher than those of comparable fat samples of intact chops. There was no consistent pattern of differences in the microflora of lean and fat samples. Differences in mean scores for surface discoloration, off odor and overall appearance of intact chops and chops without subcutaneous fat usually were either not significant (P>0·05) or inconsistent. Lean color scores of chops with or without subcutaneous fat did not differ except that chops with the subcutaneous fat removed were rated higher than intact chops during the early periods of storage. Fat color of subcutaneous fat packaged and stored separately in HOB film was often rated higher (slightly whiter) than that of comparable fat of intact chops.     

Microbiological and sensory characteristics of pork loin chops: Role of intramuscular fat

Pork loin chops of High, Intermediate and Low intramuscular fat were trimmed free of subcutaneous fat and then packaged and stored in polyvinyl chloride (PVC) film for 0-6 days or in high oxygen barrier (HOB) film for 0-28 days at 4°C ± 1°C. In general, marbling group had no (P > 0·05) effect on the aerobic plate count (APC) and did not result in major differences in the distribution of types in the microflora of pork loin chops. During storage, Pseudomonas spp. became dominant in the microflora of PVC-wrapped chops while Lactobacillus spp. became dominant in the microflora of chops stored in HOB film. Of the sensory characteristics examined, mean surface discoloration and mean overall appearance scores of chops of Low intramuscular fat stored in HOB film were usually lower (P < 0·05) than those of chops of Intermediate and High intramuscular fat. In contrast, marbling group usually had no significant effect on mean surface discoloration and mean overall appearance scores of chops packaged in PVC film.     

Influence of dietary fat on pork eating quality

This study compared the influence of dietary fat sources on meat quality, fatty acid composition and sensory attributes in pork. The experiment was conducted with 43 entire male pigs (Pietrain×(Landrace×Large White)) which were fed a basal diet without added fat (control diet) or supplemented with different sources of fat: animal fat (1%, AF1; 3%, AF3), soyabean oil (1%, SBO1) and calcium soaps of palm oil (1%, CaSPO1). Dietary fat supplementation did not significantly affect ultimate pH, colour, Warner-Bratzler shear force values, sensory attributes or SFA. Pigs fed SBO1 had the lowest proportion of MUFA and the highest of PUFA. In conclusion, these dietary fat sources could be recommended for inclusion in diets, at these levels, with no detrimental effect on eating quality. Despite finding no significant differences, the PCA afforded a comprehensive view of the predominating attributes of pork from animals fed the different fats.     

The effect of enhancement with salt, phosphate and milk proteins on the physical and sensory properties of pork loin

Pork loins were pumped to 110% of original weight with solutions containing 5.5% salt and 3.3% sodium tripolyphosphate, 5.5% salt and 3.3% β-lactoglobulin (β-lg) enriched fraction or 5.5% salt and 3.3% whey protein concentrate 80% (WPC80) for comparison with non-enhanced control loins. The enhancement of pork loins significantly increased (p<0.001) the tenderness and juiciness. Warner-Bratzler shear force values were lower (p<0.001) in enhanced then in non-enhanced control chops. The enhanced pork chops had a slightly higher overall flavour and overall acceptability to the control pork chops. Sensory analysis showed that β-lg enriched fraction and WPC80 can be used as replacement ingredients to reduce the amount of phosphate used in enhancement solutions, as they were comparable to salt/sodium tripolyphosphate (salt/STPP) enhancement solution. Consumers rated the tenderness, juiciness and taste of the enhanced chops significantly (p<0.001) higher then the control chops.     

Physico-chemical characteristics and sensory quality of two date varieties under commercial and industrial storage conditions

The physicochemical characteristics of two date palm varieties, “Khalas” and “Barhee”, commonly grown in the United Arab Emirates, were studied under commercial and industrial storage conditions. Storage conditions chosen were 2 months and 1 year at −3 °C and at room temperature (∼25 °C). Stored samples were analyzed for sugar, moisture, protein, ash and mineral element contents. Physical measurements on the date fruit, pit and flesh, measurements of the fruit's pitting pressure, shear pressure and modulus of elasticity, as well as sensory evaluation, were carried out on freshly harvested and stored samples. Significant variations in measured attributes were observed with storage treatments, but the two varieties did not behave similarly under matching storage conditions. Quality was best maintained after storage of 2 months at −3 °C for Khalas, and 1 year at −3 °C for Barhee. Overall, storage time and temperature as independent factors alone did not account for all of the observed variation in the studied attributes of Khalas and Barhee. Principal component analysis revealed that most of the variation of the stored dates comes from “size”, followed by “texture” variables. The work pointed to some probable chemical and physiological systems responsible for deterioration of dates, the understanding of which can prove extremely helpful in developing methods of short- and long-term preservation of the fruit.     

Influence of muscle type on physicochemical and sensory properties of foal meat

The effect of muscle type on physico-chemical properties and sensory characteristics of foal meat was investigated. Six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and psoas major & minor (PM) from twelve foals slaughtered at 15 months from an extensive production system in freedom regimen were extracted for this study. Regarding chemical composition, intramuscular fat content showed significant differences among muscle where PM presented higher values (0.7%) than the other ones. The heme-iron content also presented significant differences ranging between 1.5 and 2.4 mg/100 g fresh meat. ST was the lightest, while TB and PM presented a more intense redness. The muscles that had a greater capacity to hold water were ST and BF, which presented lower drip loss (2 and 2.2%) and cooking loss (17.3 and 17.2%), respectively. Textural traits established the following scale in response to the tenderness: LD > PM > ST > TB > BF > SM. Finally, sensory analyses revealed that color and texture traits (hardness, juiciness and fibrousness) were significantly influenced by muscle type.     

Physicochemical and sensory characteristics of restructured beef steak with added walnuts

The effects of different proportions (0, 5, 10, 15%) of added walnuts on the physicochemical and sensory characteristics of restructured beef steak were evaluated. The addition of 10 and 15% walnut reduced (P<0.05) cooking loss. Increasing proportions of walnut in the beef steak increased (P<0.05) water binding and reduced (P<0.05) fat binding properties. The addition of walnut did not affect (P>0.05) textural properties in uncooked restructured beef steak, but in cooked products Kramer shear force and bind strength were reduced (P<0.05) when 10% or more of walnut was added. Product morphology characteristics suggest that walnut interferes with the formation of protein network structures. Restructured steaks made with added walnut presented acceptable sensory properties. Incorporation of nuts in meat products can be use to confer potential heart-healthy benefits (Spanish Patent Application 200300367).