Consumer responses for tenderness and overall impression can be predicted by visible and near-infrared spectroscopy,Meullenet–Owens razor shear,and Warner–Bratzler shear force

Beef ribeye rolls (n = 40) from Select, low Choice, top (upper 2/3) Choice, and Prime quality grade carcasses were used to determine the relationship of visible and near-infrared spectroscopy (VNIR) reflectance, Warner–Bratzler shear force (WBSF), and Meullenet–Owens razor shear (MORS) with consumer responses for tenderness and overall impression. Steaks (2.54 cm) were cut and assigned to either 14 or 28 d aging (n = 4/aging period). Reflectance in the VNIR spectrum was measured 1 d from the box-date no less than 30 min after cutting, and prior to aging. The steak used for VNIR measurement was designated for WBSF and MORS measurement, whereas three adjacent steaks were cooked for evaluation by a consumer panel (n = 240 members). Steaks from the Select-grade ribeye rolls had the greatest (P = 0.06) WBSF values and lower (P < 0.05) overall impression scores than those from top Choice and Prime quality grades. Consumer panelists evaluated steaks aged 28 d as more tender (P < 0.05) than those aged 14 d. The relationship of mechanical tenderness measurements were higher with consumer panel responses for tenderness than with overall impression, and those relationships were stronger for the Select grade than for quality grades with higher degrees of marbling. The 2nd derivatives of VNIR measurements were more successful at predicting consumer panel responses of tenderness and overall impression than WBSF and MORS; thus, VNIR methodology was less invasive and more predictive than other, more traditional tenderness measurements.     

Efficacy of performing Warner–Bratzler and slice shear force on the same beef steak following rapid cooking

The ability to perform Warner–Bratzler and slice shear force on the same beef top loin steak was investigated. Three, 2.54-cm steaks from top loins (n = 99) were allotted to either Warner–Bratzler only (WBS), slice shear force only (SSF), or Warner–Bratzler and slice shear force (WBS/SSF). Steaks were thawed at 2 °C for 48 h prior to cooking. Steaks were cooked to 71 °C using a conveyor convection oven and allowed to cool at room temperature for a minimum of 4 h. Steaks allotted to WBS used six 1.27-cm cores and steaks allotted for WBS/SSF used four cores. Steaks allotted to SSF and WBS/SSF used one, 1 cm × 5 cm slice. Correlations among WBS and SSF for all steaks ranged from 0.49 to 0.69 (P < 0.0001). When correlations were generated for steak location within the top loin, the relationships among WBS and SSF performed in the same steak ranged from 0.53 to 0.70 (P < 0.05). These results indicate that it may be feasible to conduct WBS and SSF on the same top loin steak, and that the steak taken 2.54 cm from the 13th rib is the optimal location for this combination of procedures.     

Determination of total volatile basic nitrogen (TVB-N) content and Warner–Bratzler shear force (WBSF) in pork using Fourier transform near infrared (FT-NIR) spectroscopy

Total volatile basic nitrogen (TVB-N) content is one of important index of pork’s freshness, and Warner–Bratzler shear force (WBSF) is seen as the important index of pork’s tenderness. This paper attempted the feasibility to determine TVB-N content and WBSF in pork by Fourier transform near infrared (FT-NIR) spectroscopy. Synergy interval partial least square (SI-PLS) algorithm was performed to calibrate regression model. The number of PLS factors and the number of intervals were optimised simultaneously by cross-validation. The performance of the model was evaluated according to two correlation coefficients (R) in calibration and prediction sets. Experimental results showed that the correlations coefficients in the calibration set (R_c) and prediction set (R_p) were achieved as follows: R_c = 0.8398 and R_p = 0.8084 for TVB-N content model; R_c = 0.7533 and R_p = 0.7041 for WBSF model. The overall results demonstrated that NIR spectroscopy combined with SI-PLS could be utilised to determinate TVB-N content and WBSF in pork.     

Effects of supplementing feedlot steers and heifers with zilpaterol hydrochloride on Warner–Bratzler shear force interrelationships of steer and heifer longissimus lumborum and heifer triceps brachii and gluteus medius muscles aged for 7, 14 and 21 d

Longissimus lumborum (LL) muscles from 117 steers plus LL, gluteus medius (GM), and triceps brachii (TB) muscles from 132 heifers were evaluated for effects of feeding duration of zilpaterol hydrochloride (Zilmax®; ZH; 7.56 g/907 kg on a dry matter basis) and aging time on tenderness. Both genders were blocked by initial weight into six blocks of four pens. Pens were assigned to treatments of control (C), or 20, 30 or 40 days on ZH, with a 3 day withdrawal. Steaks from each subprimal were vacuum aged individually for 7, 14 or 21 days, frozen, thawed, and cooked to 71 °C for Warner–Bratzler shear force (WBSF). All muscles from steers and heifers from ZH30 and ZH40 treatments had higher (P < 0.05) WBSF than those of C. The WBSF of steer LL and heifer TB from the ZH20 treatment was higher (P < 0.05) than C. There was a treatment by aging interaction (P > 0.05) for WBSF of GM steaks from heifers. Percentage of intramuscular fat had little effect on tenderness. Percentages of steer LL and heifer TB steaks with WBSF values below thresholds of either 5.0 or 4.6 kg from the ZH20 treatment were quite high, whereas percentages of heifer LL and GM muscles below 5.0 kg (67%) and 4.6 kg (57%) were low. Feeding ZH ? 20 days generally increased WBSF values, but mean WBSF values for steer LL and heifer TB were below 4.6 kg. Feeding ZH 20 ? days resulted in >40% of GM steaks with WBSF values above 4.6 kg.     

Dry fermented sausages manufactured with different amounts of commercial proteinases: Evolution of total free α-NH(2)-N groups and sensory evaluation of the texture

Different doses of some commercial proteinases (Neutrase, Alcalase, HT Proteolytic and Fungal Protease) were tested in the manufacture of two types of dry fermented sausages in order to choose the highest concentration that having proteolytic effect did not show texture problems. The different units in which their activity was expressed was one of the difficulties found in this work. All of them showed proteolytic activity in these products but with different intensity, leading in some cases to an excessive softening of the sausages. The effect of Fungal Protease became apparent earlier in a 16 mm particle size sausage than in a 3 mm particle size sausage. Careful dose selection for every proteinase could make it possible to ensure a proteolytic effect that could accelerate the maturation without texture defects.     

Screening for estrogenic steroids in sheep and chicken by the application of enzyme-linked immunosorbent assay and a comparison with analysis by gas chromatography–mass spectrometry

A total of 146 sheep urine and 87 chicken muscle samples collected from birds sold in the State of Kuwait local market (originating from Brazil, Denmark, France and Turkey) were tested for residues of two xenobiotic estrogenic compounds, namely diethylstilbestrol (DES); and ethinylestradiol. The samples were analyzed using enzyme-linked immunosorbent assay (ELISA) and gas chromatography–mass spectrometry (GC–MS). Data obtained showed that the levels of DES and ethinylestradiol in the urine ranged from not-detected (ND) to 1.2 and ND to 0.90 ppb, respectively. In the chicken muscle, the levels encountered were ND to 0.70 and ND to 0.30 ppb, respectively, indicating that some samples may show some activity in terms of a residue, as recommended by international organizations. In view of the results obtained by ELISA, the employment of a cut-off value of 0.30 ppb would make it reasonable to obtain low false-positive results, thus indicating that such a technique provides a fast and reliable method for the detection and screening of anabolic samples. All samples (both negative and positive) were subjected to GC–MS analysis for confirmatory purposes. The results obtained from the GC–MS analysis were found to be negative. These results show that the activity seen and reported above was due to the matrix of the samples, but not due to the active estrogenic compounds. Data on extraction recovery and coefficient of variation are also reported.     

Development of a Sensitive and Accurate Stable Isotope Dilution Assay for the Simultaneous Determination of Free 4-Hydroxy-2-(E)-Nonenal and 4-Hydroxy-2-(E)-Hexenal in Various Food Matrices by Gas Chromatography–Mass Spectrometry

An analytical method suitable for the determination of 4-hydroxy-2-(E)-nonenal (HNE) and 4-hydroxy-2-(E)-hexenal (HHE) in various food matrices was developed and validated. The method involves the use of deuterated HNE and HHE as internal standards, extraction of the analytes from the matrices followed by derivatization and detection with gas chromatography–mass spectrometry. Four different food matrices were chosen as model systems including vegetable oils, unprocessed meat, fried potato crisps, and infant formula and three different extraction techniques suitable for the different matrices were applied including the Quick Easy Cheap Effective Rugged Safe method. The simplicity of the extraction techniques allows the method to be applied for routine analysis of a large amount of samples. The results verify the accuracy and reproducibility of the analytical technique and its ability to provide reliable quantification of both analytes at concentrations as low as 12.8 ng g^?1 in meat samples. Furthermore, a short overview of the levels of HNE and HHE in several products available in the Belgian market is presented.