155 research outputs found
Effect of hazelnut skin and dry tomato peel on the oxidative stability, chemical and sensory properties of pork burgers during refrigerated storage
The quality deterioration of meat products due to lipid oxidation could be controlled by utilizing agri-food byproducts rich in antioxidants. This study evaluated the effect of adding hazelnut skin and dry tomato peel to pork
burgers against oxidation phenomena. Three types of burgers were prepared: a control (C) with a basic
formulation, and two formulations with 2.5% hazelnut skin (HS) or with 2.5% dry tomato peel (DTP). Microbiological, sensorial, and physio-chemical analyses were performed during 7 days of refrigerated storage
(0–4 ◦C). Results showed a high inhibition of oxidation in HS burgers at all sampling times, both raw and cooked
burgers, while in DTP burgers this phenomenon occurred only when cooked. Both by-products provided a significant amount of fiber, increased the polyunsaturated fatty acids (PUFA) content, and improved the omega-6/
omega-3 ratio
Relationship between pre-slaughter handling and carcass bruising in calves. Italian Journal of Animal Science
Sono stati esaminati i tempi di svolgimento delle operazioni di carico, scarico, sosta e attesa pre-stordimento di 105 vitelli a carne bianca di razza Frisona. Inoltre, durante tali operazioni è stata rilevata la frequenza di eventi quali la caduta, l’inversione, la testata, la monta, il rifiuto di movimento, il salto, la scivolata, l’evacuazione e la vocalizzazionenonché il numero di applicazioni di pungolo elettrico. Sulle carcasse si è poi proceduto all’individuazione e alla classificazione delle lesioni superficiali utilizzando una scala a tre classi (1=assente, 2=leggera, 3=grave) allo scopo di esaminarne le relazioni con la durata delle operazioni pre-macellazione e con la frequenza degli eventi comportamentali. I tempi di svolgimento delle operazioni di scarico e di sosta hanno influenzato significativamente(P<0,01) la distribuzione delle carcasse nelle tre classi di lesioni. Inoltre, lesioni sia leggere che gravi sono risultate presenti nelle carcasse provenienti da soggetti che, in media, hanno presentato una maggior frequenza di cadute o di monte e una minor frequenza d’evacuazioni durante le operazioni pre-macellazione
Effect of different stunning methods of pigs on subcutaneous veining defect and meat quality of raw ham
Trecentocinque suini pesanti sono stati sottoposti a stordimento elettrico (146 soggetti) o con CO2 (159 soggetti) per valutare l’effetto del metodo di stordimento sull’incidenza del difetto di venatura delle cosce, sul valore del pH, sul colore dei muscoli SM e BF e su alcuni parametri ematici. Nei suini sottoposti a stordimento con CO2 si è osservata una più alta percentuale di cosce con il difetto di venatura e valori più elevati di HCT, PT e PTT. I suini storditi mediante elettronarcosi hanno presentato un pH1 più basso e un colore più chiaro nel SM
Effects of dietary level of pantothenic acid and sex on carcass, meat quality traits and fatty acid composition of thigh subcutaneous adipose tissue in Italian heavy pigs.
Two trials were carried out to evaluate the
effects of i) supranutritional doses of pantothenic
acid (PA) and ii) sex on carcass, meat
quality and fatty acid (FA) composition of subcutaneous
adipose tissue in Italian heavy pig.
In trial 1, 59 Duroc x (LxLW) pigs were fed the
same diet containing either 10 [in the control
(C) group] or 110 ppm [in the treatment (T)
group] PA, from 107 to 168 kg live weight. At
slaughtering, forty carcasses were sampled
randomly. The T carcasses had lower backfat
thickness (P<0.05), lower incidence of adipose
cuts (P<0.05), higher lean cuts percentage
(63.09 vs 60.64%; P<0.01) and lean meat yield
(P<0.07). In trial 2, 42 pigs [Dumeco Cofok x
(LxLW)], evenly divided into three groups,
were fed the same feed containing respectively
10 (C), 60 (T1) and 110 ppm (T2) PA, from 95
to 165 kg live weight. The treatment lowered
total adipose cuts yield (P<0.05) and increased
lean/adipose cuts ratio (P<0.07). In the outer
layer of thighs subcutaneous adipose tissue,
the treatment raised polyunsaturated FA content
(P<0.01), unsaturation coefficient
(P<0.01) and polyunsaturated/saturated (P/S)
FA ratio (P<0.05). In the inner layer, the treatment
led to a lower saturated FA (P<0.05) and
higher polyunsaturated FA content (P<0.01).
In both trials, females generally provided leaner
carcasses. In neither trials, vitamin level
affected meat quality. Thus, feeding high levels
of PA to heavy pigs can yield more valuable carcasses
without affecting meat quality.
However, effects on FA composition suggest
caution in adopting this practice in the Italian
heavy pig production
Natural complementary feeds in gestating and lactating sows: effects on performance and metabolic profile
Gestating and lactating sows were fed natural complementary feed with the aim to improve performance and metabolic profil
Iodine Value and Fatty Acids Determination on Pig Fat Samples by FT-NIR Spectroscopy: Benefits of Variable Selection in the Perspective of Industrial Applications
In this work, FT-NIR spectroscopy was employed to determine iodine value (IV) and fatty acids (FA) content of pig fat samples, through the combined use of signal preprocessing, multivariate calibration, and variable selection methods. In particular, the main focus was on the use of variable selection methods, both in order to improve the predictive performance of the calibration models, and to identify relevant wavelengths that could be subsequently used for the development of simple, fast, and cheap hand-held devices, able to measure IV and FA content directly on the fat without the need of any sample pretreatment. Firstly, for each property of interest, partial least squares (PLS) multivariate calibration models were calculated considering the whole spectral range and testing different signal preprocessing methods. Then, once chosen the optimal signal preprocessing method, a two-step variable selection procedure was applied. In the first step, the interval-PLS variable selection algorithm was used to calculate a set of calibration models, whose outcomes were considered altogether in the second step, in order to select the optimal calibration model. The variable selection procedure allowed to lower the number of spectral variables retained by the model, and often led to an increase of the performance in prediction of the external test set samples
The use of thermography on the slaughter-line for the assessment of pork and raw ham quality
The left and right hams of forty heavy pig carcasses were thermographed to evaluate whether surface temperature differences were related to meat and ham quality. Thermal imaging analysis showed no differences in average surface temperature among classes of pH or of L* colour co-ordinate nor among classes of ham defects such as veining and red skin. However, hams with a lower fat cover displayed a significantly warmer average temperature surface. Infrared thermography seems to be a practical and non-invasive method to detect hamswith a fat cover below the minimum requested to be submitted to the dry-curing process
Shelf life of pork from five different quality classes
A total of 117 loins were selected on the cutting line at 24 h post-mortem to study the long term shelf life (35 days, 4 °C) of vacuum packaged pork from five different quality classes (PSE: pale, soft, exudative; PFN: pale, firm, non-exudative; RSE: red, soft, exudative; RFN: red, firm, non-exudative; and DFD: dark, firm, dry). The microbial load at 0 d was not significantly different (P > 0.05) among the pork quality classes, indicating that the initial microflora was influenced by the dressing conditions at the plant, not by the meat quality class. But after 35 d of storage, total aerobic mesophilic and presumptive lactic acid bacteria counts were higher (P < 0.05) in DFD pork due to its higher ultimate pH. RSE was the second quality class most susceptible to spoilage, whereas PFN, RFN and PSE pork had similar microbial loads. Further research is needed to elucidate the causes of the shorter shelf life in RSE pork
Effect of two sous-vide cooking methods on physicochemical characteristics of Longissimus thoracis muscle from pigs fed with or without extruded linseed
Meat is recognised as a highly nutritive food. With cooking, the
meat enhances its nutritional value and becomes more digestible.
However, high cooking temperatures lead to several chemical
modifications in meat. Therefore, there is an increasing interest
in sous-vide cooking. The aim of this research was to study the
influence of two sous-vide cooking methods on physicochemical
characteristics of Longissimus thoracis (LT) muscle from 24 pigs
fed with two different diets: control group (C) had a basal barley/
soybean diet; in the linseed group (L), 5% of extruded linseed
replaced the same amount of barley. At 24 h post mortem, LT muscles
were sliced, vacuum sealed and stored at −18 °C until analysis.
Samples were cooked in water bath at two different
combinations of temperature and time: ‘A’ 80 °C of the bath water
as long as the core temperature of the pork reached 70 °C; ‘B’
60 °C for 15 h. After the cooking process, the samples were kept
under refrigeration (2 °C) for 24 h. The day after, cooking loss,
colour, pH, microbial growth and tenderness were determined.
Microbial growth was analysed also in the raw meat. Statistical
analysis was performed by means of ANOVA, using the GLM procedure
of SAS. Dietary treatment (C vs. L) and cooking condition
(A vs. B) were used as independent variables. Dietary treatments
did not produce significant differences in pH, colour, cooking loss
and tenderness. Colour parameters were affected by cooking
method: a* values of the internal part of the sample and b* values
of the external part were higher for the samples cooked at 60 °C
(a* 4.74 vs. 3.97 for B and A, respectively, p<.05; b* 17.79 vs. 15.84,
p<.01). The A cooking method led to higher (p<.01) shear force
values (5.03 vs. 3.30 kg). The microbial load in the raw meat was
significantly different (p<.05) between dietary treatments: C
group showed higher total viable count (4.56 vs. 4.14 log10) and
Enterobacteriaceae (2.65 vs. 1.94 log10) respect to L group. Low
microbial growth was detected for both cooking methods. Total
viable count was 0.50 log10 for A cooking method and 0.64 log10
for B, without significant differences among them. No
Enterobacteriaceae growth was detected. Also, no differences
were found for pH and cooking loss between A and B. Both cooking
methods generated a meat safe from contamination. The B
method: low temperature for long time also, generated tender
meat
Functional analysis finds differences on the muscle transcriptome of pigs fed an n-3 PUFA-enriched diet with or without antioxidant supplementations
Supplementing pig diets with n-3 polyunsaturated fatty acids (n-3 PUFA) may produce meat products with an increased n-3 fatty acid content, and the combined antioxidants addition could prevent lipid oxidation in the feed. However, to date, the effects of these bioactive compounds at the molecular level in porcine skeletal muscle are mostly unknown. This study aimed to analyse changes in the Longissimus thoracis transcriptome of 35 pigs fed three diets supplemented with: linseed (L); linseed, vitamin E and Selenium (LES) or linseed and plant-derived polyphenols (LPE). Pigs were reared from 80.8 \ub1 5.6 kg to 151.8 \ub1 9.9 kg. After slaughter, RNA-Seq was performed and 1182 differentially expressed genes (DEGs) were submitted to functional analysis. The L vs LES comparison did not show differences, while L vs LPE showed 1102 DEGs and LES vs LPE 80 DEGs. LPE compared to the other groups showed the highest number of up-regulated genes involved in preserving muscle metabolism and structure. Results enlighten that the combined supplementation of bioactive lipids (n-3 PUFA from linseed) with plant extracts as a source of polyphenols increases, compared to the only addition of linseed, the expression of genes involved in mRNA metabolic processes and transcriptional regulation, glucose uptake and, finally, in supporting muscle development and physiology. These results improve the knowledge of the biological effect of bioactive compounds in Longissimus thoracis muscle, and sustain the growing interest over their use in pig production
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