• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 1
  • 1
  • Tagged with
  • 8
  • 8
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Identifying beef muscles and processing treatments suitable for use in fajita application

Huerta Sanchez, Diana Lorena 02 June 2009 (has links)
Beef fajitas have become a popular food item, but the supply of traditional muscles is insufficient to meet the growing demand. There is a need for alternative muscles that have similar eating characteristics to those currently marketed as beef fajitas. Four different treatments - papain (P), blade tenderization (B), papain + blade tenderization (P+B), and control (C) - were applied to sixty USDA Choice M. diaphragma pars costalis, M. transversus abdominis, M. obliquus abdominis internus, M. rhomboideus, M. trapezius, M. latissimus, and M. serratus ventralis. Muscles were cut into sections and frozen at -10ºC for evaluation by a trained sensory panel, consumer panel, and Warner-Bratzler shear force (WBSF) measurements. Trained panelists found that regardless of muscle, the addition of papain improved palatability scores. In general, treatment tended not to affect the palatability scores of the M. diaphragma pars costalis and M. serratus ventralis, which tended to receive higher scores in comparison to the other muscles. In general, the control and blade tenderized M. trapezius received the lowest trained and consumer panel palatability scores and had the highest WBSF values (P < 0.05). Regardless of muscle (except for M. diaphragma pars costalis and M. serratus ventralis), P and P+B treatments reduced WBSF values (P < 0.05). Consumers (n=81) gave the M. transversus abdominis, M. serratus ventralis, and M. latissimus similar (P > 0.05) tenderness ratings when the P treatment was applied. Consumers tended to prefer the flavor and tenderness of beef fajita strips that were treated with P and P+B and indicated a preference to purchase muscles with these treatments. Consumers were willing to purchase M. serratus ventralis treated with P+B and M. latissimus treated with P the majority of the time. Papain improved the eating quality of the muscles studied. The M. latissimus and M. serratus ventralis when treated with papain alone or in combination with blade tenderization, performed well enough to be considered as alternatives for traditional beef fajitas.
2

Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels

Lund, Cynthia M. January 2009 (has links)
ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
3

Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels

Lund, Cynthia M. January 2009 (has links)
ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
4

Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels

Lund, Cynthia M. January 2009 (has links)
ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
5

Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels

Lund, Cynthia M. January 2009 (has links)
ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
6

Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels

Lund, Cynthia M. January 2009 (has links)
ABSTRACT A core tool of sensory science is the use of trained descriptive panels. This research describes an investigation into the role of motivation in the performance of trained panels and the use of a trained panel to develop a better understanding of the perception of Sauvignon blanc wines. Substantial investment in time and money is directed towards ensuring trained panels perform optimally. Having selected a panel, the panel leader needs to ensure that panellists provide accurate, reliable data. Panellist motivation is also an important factor to consider. While performance psychology, education and sport science fields have researched motivation extensively, knowledge about panellist motivation within sensory science is limited. However, findings from existing research in these other areas - which suggest an important role for autonomy, competence and relatedness - can be applied to sensory panels in order to increase intrinsic motivation. The initial part of the research investigated the fundamental factors that affect and influence panellists’ motivation and participation. A survey (n=74) revealed that extra income and a general interest in food were the key drivers in inspiring people to become panellists, whilst enjoyment in being a panellist, interest in food, and extra income were key drivers for people to remain panellists. In a second survey, the intrinsic motivation of seven trained panels from four countries (n=108) was assessed. External panels were found to be more intrinsically motivated than internal panels. Experienced panellists had an increased perception of competence, which is a key factor for people to be intrinsically motivated. Understanding motivational frameworks currently used in other research fields and integrating them into existing panel training protocols may enhance and sustain panellists’ intrinsic motivation. A trained panel (n=14) was then used in the second part of the thesis to identify key flavours in Sauvignon blanc wines from Australia, France, New Zealand, Spain, South Africa and USA. Sixteen characteristics were identified and measured, including sweet sweaty passionfruit, capsicum, passionfruit skin/stalk, boxwood/cat’s urine, grassy, mineral/flinty, citrus, bourbon, apple lolly/candy, tropical, mint, fresh asparagus, canned asparagus, stonefruit, apple and snowpea. Principal component analysis was used to describe differences between regions and countries. Sauvignon blanc wines from Marlborough, New Zealand (NZ), were described by tropical and sweet sweaty passionfruit characteristics, while French and South African Sauvignon blanc wines were described as having flinty/mineral and bourbon-like flavors. Chemical analyses of these wines also showed that Marlborough, NZ wines had more methoxypyrazine and thiol compounds. A consumer study (n=109) showed that New Zealanders significantly prefer New Zealand style Sauvignon blanc. The final part of this research focused on using trained panellists to explore the interactions between volatile and non-volatile wine compounds and their effects on the aroma profile of New Zealand Sauvignon blanc wine. Four volatile aroma compounds that are important in New Zealand Sauvignon blanc wine were studied (isobutyl methoxypyrazine [MIBP], 3-mercaptohexanol [3MH], 3-mercaptohexanol acetate [3MHA], and ethyl decanoate). Each of these four aroma compounds were assessed in combination with three non-volatile polyphenolic compounds commonly found in Sauvignon blanc wine: catechin, caffeic acid and quercetin. Results showed each polyphenol had a unique effect when blended with a specific aroma compound, either suppressing, accentuating, or showing little effect on the perception of the aroma compounds. The perception of MIBP, 3MH, and ethyl decanoate were largely suppressed by the added polyphenols, with a few exceptions. The perception of 3MH was accentuated with the addition of caffeic acid, and the perception of 3MHA was accentuated with the addition of catechin. The interactive effects of aroma compounds with polyphenols likely reflect non-covalent associations in the wine solution that reduce the volatility of the aroma compounds. With an understanding of the interactive effects of volatile and non-volatile compounds in wine, winemakers might optimize the impact of selected volatile compounds by managing polyphenol levels, supporting their efforts to attain desirable wine aroma profiles.
7

Le "goût" du cidre : Exploration des interactions entre les composés chimiques et les caractéristiques organoleptiques des cidres / The “cider flavor” : Interactions between chemical coumpounds and sensory properties of ciders

Symoneaux, Ronan 20 April 2015 (has links)
L’objectif de cette thèse est d’étudier l’influence des procyanidines, du sucre, de l’acide, de l’éthanol, des arômes et du CO2 sur le goût sucré, l’acidité, l’amertume et l’astringence du cidre. Des plans d’expériences ont été réalisés en solutions modèles et avec des cidres commerciaux afin d’étudier les effets directs des composés chimiques mais également les interactions entre eux sur la perception de ces quatre attributs sensoriels.Les résultats confirment le rôle déterminant des procyanidines,du sucre, de l’acide, de l’éthanol sur les quatre caractéristiques organoleptiques étudiées. Il faut souligner l’influence de la concentration et du degré de polymérisation des procyanidines qui modifient les perceptions sucrées et acides. Ces travaux montrent également une sur expression de l’amertume pour les procyanidines tétramères et pentamères mais seulement pour des concentrations de 750 mg/L, et une interaction entre la concentration et le degré de polymérisation pour l’astringence.Excepté pour l’amertume, la présence de gaz carbonique modifie la perception sensorielle des échantillons testés :l’astringence augmente, le goût sucré diminue pour les solutions les plus sucrées et finalement, il semble que les dégustateurs aient plus de mal percevoir les différences d’acidité entre les échantillons. Enfin, les arômes peuvent modifier la perception du goût sucré de certains cidres par un effet de congruence. En effet, la présence de notes aromatiques « fruitées » est accompagnée d’une surévaluation du goût sucré et des notes « terreux-foin »conduisent à une diminution du goût sucré perçu. Cependant,ce phénomène de congruence semble être concentration dépendante. / The aim of this thesis is to study the influence of procyanidins, sugar, acid, ethanol, CO2 and aroma on the perception of sweetness, sourness, bitterness and astringency of cider. Experimental designs were carried out with model solutions or commercial ciders to study the direct effects and interactions of the chemical compounds on these four organoleptic characteristics.The results confirm the key role of procyanidins, sugar,acid, ethanol on the four organoleptic characteristics. We notably underline the influence of procyanidins concentration and polymerization degree on sweetness and sourness when literature only focused on bitterness and astringency. Our works also indicate an overexpression of bitterness for tetrameric and pentameric procyanidins but only for concentration of 750 mg/L, and an interaction between concentration and polymerization degree for astringency.Except for bitterness, adding CO2 modify sensorycharacteristics of the samples: astringency increases,sweetness decreases for the sweetest solutions and it seems that tasters have more difficulty perceive acidity differences between samples. Finally, the aromatic characteristics can modify sweetness perception of some ciders due to acongruency effect. Indeed, “fruity” notes generate an over evaluation of sweetness when “hay-earthy”aromas lead to a decrease of this taste. Nevertheless,this phenomenon appears to be concentration dependent.
8

Combined Tumbling and Postmortem Aging to Improve Fresh Beef Quality, Palatability, and Proteolysis

Jacob R Tuell (12401446) 20 April 2022 (has links)
<p>  </p> <p>Tenderness is a key sensory trait influencing beef palatability. Tumbling is a value-adding process that has been extensively applied and studied within the realm of processed meats. Various post-harvest strategies to ensure fresh beef reaches acceptable levels of tenderness have been employed, often with the aim of physically disrupting myofibrillar structure or enhancing the rate and extent of postmortem proteolysis. One such method would be the application of postmortem aging; however, the effectiveness of aging on tenderization is well-known to differ throughout individual muscles of the beef carcass. For inherently tough cuts, physical interventions such as mechanical tenderization are often used, although several detriments to quality attributes may be induced. Further, some modern consumers prefer meat products with no added non-meat ingredients. An alternative method of applying tumbling in the absence of a brine solution followed by additional postmortem aging could be a practical means to facilitate tenderization while potentially minimizing detriments to other eating quality attributes.</p> <p>To evaluate the efficacy of tumbling without brine a method of beef tenderization, the process was first assessed in the <em>longissimus lumborum </em>muscle (n=9). In this study, muscles were allocated among 0, 60, and 90 minutes of tumbling, after which aging for 0, 7, and 14 days was conducted. Immediately after the application of the tumbling process, steaks from muscles that had been tumbled were considerably more tender (24.7 N and 21.6 N for 60 and 90 minutes, respectively) than non-tumbled controls (34.8 N). Steaks from the tumbled groups maintained greater instrumental tenderness throughout the course of the aging period. These results were supported by increases in myofibril fragmentation index, as well as increased troponin-T degradation during aging. However, cooking loss was increased in tumbled steaks, which could have implications for sensory juiciness. Considering this study demonstrated that tumbling without brine inclusion followed by postmortem aging resulted in profound changes to sensory traits, further study regarding its impacts on sensory attributes and proteolysis among different beef muscles was warranted.</p> <p>The following study evaluated the combined tumbling and aging process on the quality, palatability, and proteolytic attributes of beef <em>longissimus lumborum </em>and <em>semitendinosus </em>muscles (n=16). Muscle sections were allocated among 0, 40, 80, and 120 minutes of tumbling, as well as 0 or 10 days of subsequent aging. Regardless of aging duration, tumbling for any duration increased instrumental tenderness of the <em>longissimus lumborum</em> but not <em>semitendinosus</em> muscle. Similar to the previous study, increased cooking loss was induced through tumbling. In both muscles, obvious fragmentation of the myofibrillar structure with tumbling was observed through increases in myofibril fragmentation index and transmission electron microscopy. Tumbling with aging favored the degradation of myofibrillar proteins including troponin-T and desmin; however, calpain-1 autolysis appeared mostly unchanged. Neither tumbling nor aging influenced the amount and properties of collagen, which may indicate why the process did not influence instrumental tenderness of the <em>semitendinosus </em>despite myofibrillar fragmentation and degradation. <em>Longissimus lumborum </em>muscles tumbled for any durations were rated by consumers (n=120) to be more tender with greater overall liking than control steaks. <em>Semitendinosus </em>steaks that were tumbled for 120 minutes and further aged had improved liking of tenderness with similar juiciness and flavor to control steaks at the same postmortem timepoint. These results indicated that tumbling without brine would result in myofibrillar fragmentation and favor the degradation of myofibrillar proteins during aging, while impacts on connective tissues would be minimal. Consequently, muscles without a high extent of background toughness would be effectively tenderized through tumbling, while the results would be more limited in inherently tough cuts.</p> <p>Considering these results, the process was then applied to muscles of intermediate tenderness from the sirloin, specifically the <em>gluteus medius, biceps femoris, </em>and <em>tensor fasciae latae </em>muscles (n=16). Muscles were tumbled for 0 or 120 minutes, then aged for 0 or 10 additional days. Tumbling increased the instrumental tenderness of the <em>gluteus medius </em>and <em>tensor fasciae latae </em>but not the <em>biceps femoris</em>, regardless of aging time. Cooking loss was increased with tumbling in all muscles. Similarly, myofibrillar fragmentation was also increased in all muscles, and there was some evidence to suggest that tumbling with subsequent aging would aid in the degradation of troponin-T in the <em>biceps femoris</em>. To further understand how tumbling might affect specific descriptive sensory attributes, a trained panel (n=8) was conducted on aged samples. Tumbled <em>gluteus medius </em>steaks had greater myofibrillar tenderness than non-tumbled controls; however, tenderness scores of other muscles were not affected. There was some evidence that tumbling with aging could induce the generation of off-flavors in the <em>gluteus medius </em>and <em>tensor fasciae latae</em>, as well as decrease juiciness of the <em>biceps femoris</em>.</p> <p>Taken together, these results support that tumbling without brine inclusion would be an effective strategy to improve beef tenderness and palatability, dependent on the traits of the individual cut. Improved tenderness would be primarily attributed to the fragmentation and degradation of myofibrillar structure. However, the results indicate that tenderization would be limited in cuts with a high extent of background toughness, which tumbling alone would be largely unable to disrupt. Future studies should focus on the effects of tumbling without brine inclusion with aging on oxidative stability and the potential introduction of hazards prior to industry application. Further elucidation of how the process could be optimized to maximize tenderization while minimizing potential negative impacts to flavor and juiciness would be beneficial to improving overall palatability.</p>

Page generated in 0.0629 seconds