Eduardo Francisquine Delgado

Percepção pelos consumidores brasileiros da maciez da carne classificada pela força de cisalhamento e sabor

The knowledge of consumer perception of meat tenderness and taste is essential to forecast a Brazilian quality value-based beef market. This study aimed to verify perception of tender (WBSF 4.8 kg) strip loin steak or uncharacteristic (calcium-treated/Ca-IM) and normal (non-calcium/NO-Ca) meat taste by consumers according to gender, age, education and income levels. Steaks were previously classified by shear force measurements as tender or tough. Each consumer was served a paired sample of one tender and of one tough steak, which were either Ca-IM or NO-Ca treated before tenderness classification. Three hundred and eight consumers answered a nine-point intensity (tenderness) and hedonic (taste) scales evaluation questionnaire. Among consumers, 82.2% indicated beef as first choice meat products, 75.3% had beef at least four times a week; 39.3% considered taste as the most important meat attribute and 30.2% considered tenderness; 75.8% were males; 73.6% were 21 to 55 years old; 56.7% had college education; 76.6% had monthly income higher than US

Intestinal histomorphology in Pseudoplatystoma fasciatum fed bovine colostrum as source of protein and bioactive peptides

435,00. Tender steaks were scored highest (P < 0.01), independently of gender, age and income. However, elderly consumers gave higher scores to tender steaks in comparison to middle age consumers (P < 0.05). In the lower education level, scores given to tender and tough meat did not differ. The higher income level responders assigned lower tenderness scores within tender or tough meat (P = 0.10). Differences in taste were perceived by both genders, and by consumers in every income and education level. Males gave higher scores (dislike less) within Ca-IM steaks. Consumers in the lower education level scored taste higher (like most) within untreated samples. The elderly people could not differentiate taste between the Ca-IM and NO-Ca steaks. These are the first indications that Brazilian consumers perceive tender from tough or uncharacteristic taste of beef, but palatability is evaluated differentially depending on gender, age, education and income level.

Desenvolvimento intestinal de bezerros recém-nascidos aleitados com colostro de vacas tratadas com rbST

Histological responses of the intestine are key for evaluating nutritional value of feed ingredients, since the organ is not only the chief site of feed digestion and nutrient absorption but also plays an important immunological function. Histomorphological alterations were evaluated in the intestine of juvenile striped catfish, Pseudoplatystoma fasciatum, fed diets containing 0 (control), 10 or 20% inclusion of lyophilized bovine colostrum (LBC), as source of protein or bioactive peptides, for either 30 or 60 days. Fish fed 20LBC presented at 60d a distinct pattern of macrophages and, some of them, higher number of vacuoles in rectum mucosa. The thickness of the muscle layer (TML) in fish fed diets with LBC was higher in the first portion of medium intestine than fish fed 0LBC. All fish presented significant increase of TML in the second portion of medium intestine along feeding period, but fish fed 20LBC had smaller values of TML than those of fish fed 0 and 10LBC which might be related to the higher intestinal coefficient found for this group. The TML of rectum was higher just for fish fed 10LBC. Dietary LBC altered morphometrical features of juvenile striped catfish intestine and possibly induced inflammatory reaction in the rectal mucosa, as a function of level of inclusion, feeding period and segment of intestine analyzed.

Influence of feeding regime and finishing system on lamb muscle fiber and meat quality

With the objective of evaluating different levels of IGF-I on the hepatical and intestinal indicators of cellular activity in newborn calves, 42 pregnant Holstein cows were randomly assigned to two groups: a) control: injection of vitamin E or b) rbST: injection of growth hormone (rbST). Injections started 35 days pre-partum and were repeated every 14 days until parturition. Newborn calves were randomly assigned to a 2 x 3 factorial arrangement of treatments (two mother groups and three different ages). After slaughter, samples from liver, jejunum and ileum were collected. Calves from rbST group showed lower levels of DNA and protein in jejunum at seven days of age, while protein concentration increased at two days of age. Similar response was observed for the ratio of protein/RNA in jejunum. In the control group, the increase in protein concentration was observed in the seventh day of age. The indicators of cellular activity measured in this trial suggested that greater IGF-I concentration in colostrum of rbST treated cows promoted intestinal cellular maturation by affecting behavior of first generation enterocytes.

Effect of growth hormone on fatty acid synthase gene expression in porcine adipose tissue cultures

The study verified the influence of different nutritional levels of the dams, before parturition, the weaning age of the lambs and the finishing system on lamb muscle fiber morphology and meat quality. Ile-de-France × Bergamacia crossbred dams grazing on natural grassland were divided into two groups: 1) nutritional supplement 30 days before the parturition (SUPL), and 2) no nutritional supplement (NS). These groups were further subdivided by weaning age of the lambs, which corresponded to either 45 or 60 days. The weaned lambs from each of the previous groups were also divided into different finishing systems: confined and fed a complete diet (CD), confined and fed hay (H) and kept on grassland (P). The lambs were slaughtered at 30 kg live weight (CD and P), or at 150 days of age (H). The carcasses were cooled at 4oC/24h. The analyzed variables were: longissimus dorsi muscle fiber morphophysiology, post mortem myofibrillar fragmentation (at 0, 3 and 7 days post mortem), meat pH and temperature. There was no effect of supplementation of dams or weaning age of the lambs for the evaluated variables. The frequency of slow-oxidative (SO), fast-oxidative-glycolytic (FOG) and fast-glycolytic (FG) muscle fiber types was not altered by the treatments, but the fiber cross-sectional area was smaller for the lambs finished only on hay, and the meat pH values and temperature were lower and the myofibrill fragment dimensions were smaller. As time maturation increased from 0 to 3 and 7 days post mortem, there was a decrease in the length of the myofibrill fragments. The diet of the lambs which were maintained confined and fed only with hay was nutritionally inferior when compared with all the others, and this changed the quality of the meat compared to the finishing systems on grassland or confined and fed complete diet.

Taxa de crescimento e fragmentação Miofibrilar diferenciadas em ratos submetidos a restrição alimentar e realimentação

Abstract We describe an efficient in vitro assay to test growth hormone effects on mRNA levels and fatty acid synthase (FAS,EC. 2.3.1.85) activity. Swine adipose tissue explants were long-term cultured in medium containing growth hormoneand FAS mRNA levels and enzyme activity were measured. We quantified FAS transcripts by competitive reversetranscriptase PCR (RT-PCR) using total RNA from cultured adipose tissue explants and RT-PCR standard-curveswere constructed using a cloned 307 bp segment of native FAS cDNA and a shorter fragment from which a 64 bp(competitor, 243 bp) internal sequence had been deleted. A known amount of competitor was added to each PCR asan internal control and -actin transcripts were also measured to correct for differences in total RNA extraction andreverse transcription efficiency. In cultures with added growth hormone FAS mRNA levels decreased 70% (p < 0.01)and FAS enzyme activity decreased 22% (p < 0.05). These in vitro growth hormone effects were consistent withthose observed

Sarcoplasmatic and myofibrillar protein changes caused by acute heat stress in broiler chicken

Feed regimens alter muscle growth rate, hence they might impact the proteolytic system involved in tenderization during meat conditioning. The aim of this project was to verify the effects of feed restriction regimens on muscular and animal growth and their impact on postmortem myofibrillar fragmentation. The regimens were: 1) Feeding ad libitum for 11 d (Al/2); 2) Feed restriction (60% of Net Energy for maintenance - NEm) for 11 d (Rt/2); 3) Ad libitum for 22 d (Al); 4) Ad libitum for 4 d and feed restriction (60% NEm) for 18 d (Rt); 5) Ad libitum for 19 d and 3 d of fast (Ft); 6) Feed restriction (60% NEm) for 11 d and ad libitum until 22 d (Ral). The regimens Al/2 and Rt/2 had different intestine weights (19.3 ± 1.1 and 15.8 ± 1.9 g, respectively; P < 0.07). At 22 d, Al animals had higher (P < 0.07) intestine weight (21.8 ± 3.8). Moreover, Ral animals had heavier intestine (19.9 ± 1.5) as compared to Rt (16.6 ± 1.6) or Ft (12.8 ± 1.9). The intestine/live weight percentage ratio was lower (P < 0.05) for Ft (6.3%) as compared to Al (8.4%) and to Ral (9.2%), but it was similar to Rt (7.6%). Liver weight (g) in the Ral (9.5 ± 1.1) did not differ from Al (10.7 ± 2.5) or Rt (8.5 ± 1.1), although the two latter were different (P < 0.05). There was an effect of feed restriction over muscle protein degradation verified by Myofibrillar Fragmentation Index (MFI). The animals at Rt, Ft or Ral showed the lowest MFI 0d (42 ± 1.9; 40 ± 2.7; 40 ± 3.6; respectively) and MFI 5d (77 ± 2.7; 74 ± 3.0; 74 ± 2.9; respectively) as compared to Al, whose indexes were 54 ± 3.0 and 82 ± 3.3. Even though the MFI 5d were lower for the restricted animals, the rates of fragmentation postmortem were higher. Feed restriction altered myofibrillar protein degradation, reflected in lower extended fragmentation of the myofibrils.

Imunocastração e ractopamina na qualidade de lombos suínos processados com sal e tripolifosfato

ABSTRACT: Acute heat stress (AHS) modifies the structure of myofibrils affecting functionalproperties of meat, mainly the water holding capacity. This experiment aimed to identify changes inproteolysis and migration between the myofibrillar and sarcoplasmatic fractions due to pre-slaughterAHS. Myofibrillar fragmentation index (MFI), SDS-PAGE, western blot of vinculin (WB) and shearforce (SF) were determined. Six hundred broilers ( Gallus gallus ) were slaughtered in three differentdays (ST). In each ST, groups of ten animals were placed in transport crates and submitted to AHS(35oC, 75 - 85% RH) for 2 hours. Simultaneously, the non-stressed broilers (NS) were kept in thermoneutralenvironment (22oC, 83 ± 6.6% RH) within the crates in the same density. After slaughter, the breastmuscles were kept refrigerated until the withdrawal of all samples (0, 1, 2, 6 and 24 hours after slaughter).Sampling within AHS and NS birds was collected according to lightness value (normal L*≤ 49, andhigh ≥ 51), except for determination of MFI and SF. The lightness was used later to perform SDS-PAGEand WB analyses. MFI kinetics showed that the fragmentation rate was superior in animals NS,indicating that AHS can harm proteolysis and rate of myofibrillar fragmentation. However, the extentof fragmentation did not change, as well as SF values. SDS-PAGE for Troponin fragments indicated adifferentiated pattern between AHS and NS. The WB did not show alterations in vinculin fragmentation.Modifications in sarcoplasmatic fraction are observed in meat with high L*values, independent ofenvironmental condition.Key words: broiler, heat stress, lightness, fragmentation index, shear force

Acute heat stress detrimental effects transpose high mortality rate and affecting broiler breast meat quality

O objetivo deste trabalho foi avaliar o efeito da imunocastracao e da suplementacao com ractopamina na qualidade do lombo suino processado com sal e tripolifosfato de sodio. Osxa0tratamentos consistiram de condicao sexual dos suinos (femeas, machos castrados fisicamente e imunocastrados) e suplementacao ou nao com ractopamina na dieta de terminacao. Osxa0cortes de lombos submetidos ao processamento com tripolifosfato de sodio e sal foram avaliados quanto aos parâmetros fisico‑quimicos, microbiologicos e sensoriais. Nao houve interacao entre condicao sexual e ractopamina nas caracteristicas do lombo cru. Axa0adicao de ractopamina na dieta aumentou a forca de cisalhamento dos lombos crus. Tambem nao houve efeito da condicao sexual nem da ractopamina na perda de peso por exsudacao e no teor proteico dos lombos. Lombos de animais imunocastrados apresentaram menor perda de peso por coccao, enquanto lombos de animais nao suplementados com ractopamina apresentaram maior umidade do que os dos suplementados. Oxa0processamento diminuiu a forca de cisalhamento dos cortes, que foi menor nos animais imunocastrados sem suplementacao com ractopamina. Axa0imunocastracao proporcionou lombos com altos valores de a* e L*. Diferencas na aparencia e na textura dos lombos suinos, independentemente da condicao sexual e da ractopamina, nao sao percebidas pelos consumidores, o que mostra que o processamento padroniza os cortes.

Pork loin two-toning and drip loss in relation to steak cross-section anatomical position, plasma and exudate glucose

Acute heat stress may affect the quality of broilers meat, however there are no reports considering thermal conditions commercially available in Brazil. In this way, the present work aimed to fill this gap of industrial relevance. Broilers of commercial strain (Cobb 500, n = 540) were randomly assigned to two thermal conditions: acute heat stress (AHS; 35°C; 75 – 85% relative humidity) and not-heat-stress (NS; 22oC; 83 ± 6.6% relative humidity), for 2 hours prior to slaughter. The mortality rate for AHS broilers reached 37%, which was greater than 5.2% verified for NS. According to the mean values, the broiler chickens were not totally affected in the parameters of pH24h, lightness (L*), cooking loss, and shear force. However, the distributions of data show great variability in the values of pH24h, L* and water holding capacity (WHC) for AHS broilers. It is suggested that AHS broilers, at severe conditions which result in increased mortality, present breast meat with greater incidence of higher pH24h, and lower lightness and WHC values.