Carolina E. Realini

Prediction of color, texture, and sensory characteristics of beef steaks by visible and near infrared reflectance spectroscopy. A feasibility study.

Color, instrumental texture, and sensory attributes of steaks from 24 beef carcasses at 2, 4, 8, 14, and 21 days post mortem were predicted by visible/near infrared (visible/NIR) reflectance spectroscopy in 400-1080 nm region. Predicting the Hunter a, b, and E* yielded the coefficient of determination (R(2)) in calibration to be 0.78-0.90, and R(2) was between 0.49 and 0.55 for tenderness, Hunter L, sensory chewiness and juiciness. The prediction R(2) for tenderness was in the range of 0.22-0.72 when the samples were segregated according to the aging days. Based on partial least square (PLS) model predicted tenderness, beef samples were classified into tender and tough classes with a correct classification of 83%. Soft independent modeling of class analogy of principal component analysis (SIMCA/PCA) model of measured tenderness showed great promise in the classification of tender and tough meats with over 96% success.

Active and intelligent packaging systems for a modern society

Active and intelligent packaging systems are continuously evolving in response to growing challenges from a modern society. This article reviews: (1) the different categories of active and intelligent packaging concepts and currently available commercial applications, (2) latest packaging research trends and innovations, and (3) the growth perspectives of the active and intelligent packaging market. Active packaging aiming at extending shelf life or improving safety while maintaining quality is progressing towards the incorporation of natural active agents into more sustainable packaging materials. Intelligent packaging systems which monitor the condition of the packed food or its environment are progressing towards more cost-effective, convenient and integrated systems to provide innovative packaging solutions. Market growth is expected for active packaging with leading shares for moisture absorbers, oxygen scavengers, microwave susceptors and antimicrobial packaging. The market for intelligent packaging is also promising with strong gains for time-temperature indicator labels and advancements in the integration of intelligent concepts into packaging materials.

Effect of vitamin C addition to ground beef from grass-fed or grain-fed sources on color and lipid stability, and prediction of fatty acid composition by near-infrared reflectance analysis.

Research was conducted to determine the effect of postmortem vitamin C addition (VITC) versus no VITC (CONTROL) to ground beef from grass-fed (GRASS) or grain-fed (GRAIN) sources on color and lipid stability during 8 days of illuminated display at 4 °C. The use of near-infrared reflectance (NIR) spectroscopy to predict the fatty acid composition of ground beef and its potential to discriminate samples from different nutritional backgrounds were also evaluated. Total lipid content of ground beef was 53% lower (P<0.05) for GRASS than GRAIN. Ground beef from GRASS had greater (P<0.01) percentages of saturated (SFA) and polyunsaturated (PUFA) fatty acids, and lower (P<0.01) percentages of monounsaturated (MUFA) fatty acids than GRAIN. For GRAIN, VITC reduced (P<0.01) lipid oxidation, and resulted in darker (P<0.01) and redder (P<0.01) color of the ground beef from 2 to 8 days of display compared to CONTROL. For GRASS, lipid oxidation did not differ (P>0.05) for VITC and CONTROL. VITC improved (P<0.01) color stability by prolonging more red color in GRASS during 8 days of display. Results from partial least squares modeling showed accurate predictions using NIR for total saturated [standard error of performance (SEP=1.16%), coefficient of determination on the validation set (r(2)=0.87)] and unsaturated (SEP=1.18% and r(2)=0.90) fatty acid contents of ground beef, as well as the composition of stearic, oleic, and linolenic (SEP=1.2%, 1.27%, and 0.07%; r(2)=0.91, 0.92, and 0.93, respectively). However, the composition of other individual fatty acids was poorly predicted. VITC was effective in retarding pigment oxidation in ground beef from both GRAIN and GRASS; however, VITC reduced lipid oxidation in GRAIN samples only, despite higher PUFA percentages in GRASS. NIR can be used to predict accurately the content of total saturated and unsaturated, and stearic, oleic, and linolenic fatty acids in ground beef. NIR showed potential to discriminate meat samples originating from different feeding production systems.

Effect of aging time in vacuum on tenderness, and color and lipid stability of beef from mature cows during display in high oxygen atmosphere package.

The effect of aging time in vacuum on tenderness, and lipid and color stability of modified-atmosphere packaged (MAP) beef during display was evaluated in eight Friesian mature cows. Longissimus thoracis et lumborum (LTL) sections were vacuum packaged and aged for 0, 3, 6, 8, 14 and 21 days. After each aging time, the LTL sections were cut into steaks and packaged in high oxygen atmosphere (80% O2: 20% CO2). Meat shear force, and color and lipid stability were evaluated at 0, 3, 6, and 9 days of simulated retail display. Aging for 6 or 8 days improved beef tenderness with color stability, instrumental discoloration (R630-R580) and visual color evaluation in MAP similar to those of short-time aged (3 d) or un-aged (0 d) beef. Longer aging times (14 and 21 d) resulted in tenderness values similar to those obtained with meat aged for 8 days but affected negatively color and lipid stability and, consequently, reduced the shelf life of beef in MAP.

Towards models for the prediction of beef meat quality during cooking

Heating of beef muscles modifies the water content, the micronutrient content and the colour of beef meat. Juice expelling and loss of water soluble micronutrients were predicted by combined transfer-kinetics models. Kinetics modeling and crust formation are needed to progress toward a reliable prediction of HAAs formation. HAAs formation in uniformly heated beef meat slices was compared with the values issued from the kinetic models developed in literature in liquid systems. The models of literature were adapted to meat slices but the parameter values were different from those determined in liquid systems. Results in meat slices were confronted to the HAAs formation at the surface of bigger meat pieces subjected to air roasting conditions. The transposition of the results from the meat slices towards the bigger meat pieces was not direct because the formation of HAAs was affected by the thickening of the crust and the migration of precursors.

Effect of whole linseed and rumen-protected conjugated linoleic acid enriched diets on feedlot performance, carcass characteristics, and adipose tissue development in young Holstein bulls

Forty-eight young Holstein bulls (slaughtered at 458.6±9.79 kg body weight) were used to evaluate the effect of whole linseed and conjugated linoleic acid (CLA) supplementation on animal performance, adipose tissue development, and carcass characteristics. The animals were fed with one of four isoenergetic and isoproteic diets: control (0% linseed, 0% CLA), linseed (10% linseed, 0% CLA), CLA (0% linseed, 2% CLA), and linseed plus CLA (10% linseed, 2% CLA). Animal performance and carcass characteristics were unaffected by diet composition. Adding linseed or CLA to the concentrate diet did not result in significant differences in adipocyte size and number or lipogenic enzyme activity. However, while the frequency distribution of subcutaneous adipocyte diameters followed a normal distribution, the frequency distribution of intramuscular adipocyte diameters was not normal in any dietary group (skewness coefficients: 0.8, 1.2, 0.9, 0.8 for control, linseed, CLA, and linseed plus CLA, respectively; P<0.05), indicative of adipocyte proliferation in the intramuscular adipose tissue.

Influence of PA6 nanocomposite films on the stability of vacuum-aged beef loins during storage in modified atmospheres

A masterbatch of polyamide 6 (PA6) containing dispersed nanoclays, was used to fabricate a novel multilayer film for vacuum packed meat. Performance of the nanocomposite was compared to a control PA6 multilayer and a high barrier commercial film. Addition of nanoclays improved oxygen barrier properties, UV-blocking capability and stiffness. Beef loins were vacuum-aged using the three films for 0 7, 14 and 21 days at 2°C. After each ageing time, beef steaks were packaged in commercial trays and high oxygen atmosphere and stored at 4°C for 9 days. Beef quality parameters and gas content were studied during display time in MAP (1, 3, 6 and 9 d). Beef quality parameters were not influenced by the packaging materials used during ageing and the performance of nanocomposites was comparable to high barrier films. Ageing had a positive impact on the stabilization of redness up to day 6 in MAP. Thereafter, oxymyoglobin content and oxidation levels were negatively influenced by ageing.

Effect of marination and microwave heating on the quality of Semimembranosus and Semitendinosus muscles from Friesian mature cows.

Semimembranosus (SM) and Semitendinosus (ST) muscles from 8 mature cows were used to evaluate the effect of marination, power of microwave heating, and internal temperature of cooking on the quality of calibrated beef roasts. Four treatments, using combinations of power (182W and 654W) and temperature (60 and 80°C) were applied to marinated (10% added brine: salt, sodium lactate, lactose, and ascorbate) and control roasts from SM (15×5×3cm) and ST (10×4×3cm) muscles in a 2×2×2 factorial arrangement. Microwave cooking was heterogeneous resulting in a gradient of temperatures within the roasts. Either high or low microwave power were appropriate for cooking ST roasts, but SM roasts cooked at 654W showed higher cooking losses, and lighter and less red cooked color than 182W. Cooking to 80°C increased cooking and color losses in both muscles and decreased tenderness of SM roasts compared with 60°C. Marination can be used successfully to enhance beef tenderness of ST and SM muscles cooked in microwave.

Effects of Enrichment with Polyunsaturated Fatty Acids (Omega-3 and Conjugated Linoleic Acid) on Consumer Liking of Beef Aged for 7 or 21 d Evaluated at Different Locations

The effect of different animal diets supplemented with linseed (source of omega-3 fatty acids: n-3) and/or conjugated linoleic acid (CON: control, LIN: 10% linseed, CLA: 2% conjugated linoleic acid, LINCLA: 10% linseed plus 2% CLA) on consumer liking of beef aged for 7 or 21 d was assessed in 3 Spanish cities. Overall, tenderness, juiciness, and flavor liking of beef were evaluated by consumers (n = 720) using 9-point scales. Hedonic scores assigned by consumers did not differ (P > 0.05) for beef from animals fed the different diets and aged for 7 or 21 d. Consumer scores showed an increasing trend in beef liking with aging time. Consumers from Pamplona assigned lower (P < 0.05) hedonic scores for beef liking than consumers from Barcelona and Zaragoza. Linseed and/or CLA can be fed to improve the fatty acid profile in beef with minimal impact on consumer liking. Consumer ratings seem to depend on regional tastes and preferences.

Shelf life of ground beef enriched with omega-3 and/or conjugated linoleic acid and use of grape seed extract to inhibit lipid oxidation

Abstract The shelf life and oxidative stability of refrigerated raw ground beef enriched with omega‐3 and/or conjugated linoleic acid (CLA) were studied. Grape seed extract (GSE) was used to inhibit lipid oxidation in the ground beef. Eight treatments of ground beef were established according to the enrichment of beef (control, enriched with omega‐3, with CLA, or with omega‐3 plus CLA) and the use of GSE (0 and 250 mg GSE/kg product). Fresh beef was ground and mixed with GSE and salt. Treatments of beef were stored at 2 ± 1°C in aerobic packaging for 0, 1, 3, and 6 days under retail display conditions. Oxidation stability (thiobarbituric acid‐reactive substances [TBARS]), pH, instrumental color, metmyoglobin formation, and sensory attributes (color and odor) were measured. Omega‐3‐enriched beef increased the oxidation level at day 6 as determined by TBARS (P < 0.05), but the instrumental color was not affected. The enrichment of CLA improved the coordinates of color (P < 0.05) until day 3 and decreased the oxidation at day 6 (P < 0.05). There were no differences in color and odor values among the types of beef during display, except at day 3, when CLA treatments had the highest scores. Addition of GSE decreased the oxidation level (P < 0.001) and did not affect the instrumental color or the sensory parameters.