María Dolores Garrido

Ascorbate, green tea and grape seed extracts increase the shelf life of low sulphite beef patties.

Green tea (GTE) and grape seed (GSE) extracts are proposed as preservatives for increasing the shelf life of low sulphite raw beef patties. The antioxidant and antimicrobial activities of both extracts were compared with ascorbate. Five groups were established for the patties: Control (with no additives), S (100 SO(2)), SA (100 SO(2)+400 sodium ascorbate), ST (100 SO(2)+300 GTE) and SG (100 SO(2)+300 GSE) (mg per kg of meat). Patties were stored at 4°C in aerobic packaging for 0, 3, 6 or 9 days under retail display conditions. Meat spoilage (total viable and coliform counts, pH, lightness, chroma, hue angle, metmyoglobin and TBARS) was determined. The sensory contribution of the extracts to cooked patties was evaluated (colour, odour, flavour and texture). The results pointed to the possibility of using low SO(2)-vegetable extract combinations to preserve raw meat products. ST, SG and SA delayed microbial spoilage, redness loss and lipid oxidation, thus increasing the shelf life of the raw sulphite beef patties by 3 days. ST, SG and SA also delayed the onset of rancid flavours in cooked patties. No anomalous sensory traits were caused by either extract. Ascorbate, GTE and GSE improved the preservative effects of SO(2) on beef patties, especially against meat oxidation. This suggested that the quantity of SO(2) added can be reduced to obtain healthier raw meat products.

Dietary administration of ewe diets with a distillate from rosemary leaves (Rosmarinus officinalis L.): Influence on lamb meat quality

The effect of including distilled rosemary leaf in the diet of pregnant ewes on subsequent lamb meat quality was studied. Thirty-six Segureña ewes were randomly assigned to three homogeneous groups. One group was fed a basal diet (BD) as control while the diet of the other two groups was modified by substituting 10% (R(1)) and 20% (R(2)) of the BD with a pellet made from 50% barley and 50% of distilled rosemary leaves (DRL). Meat spoilage (TVC, PSY and MYC), TBARS, CIELab coordinates and the sensory characteristics contribution of fresh lamb meat packed in MAP (70% O(2):30% CO(2)) were analyzed on days 0, 7, 14 and 21. In general, R(1) and R(2) had higher a* values, better scores for meat and fat colour (P<0.05) and lower TBARS and rancid odour (P<0.05), than the control samples. The total viable count was lower in meat DRL. No statistically significant differences were detected between the two treatments (10-20% DRL).

Antioxidant and emulsifying properties of alcalase-hydrolyzed potato proteins in meat emulsions with different fat concentrations

The effect of hydrolyzed potato protein (HPP), a natural antioxidant, on emulsion quality was investigated using a factorial design with two Fat (15%, 30%) and two HPP (0%, 2.5%) levels, with three replications. The colour of the raw emulsions as well as cooking losses, textural properties and TBARS of cooked frankfurters were measured. Increasing the Fat proportion significantly (P<0.05) increased L(∗), H(ab)(0) and decreased a(∗), b(∗), C(ab)(∗) and hardness. Meat emulsions with added HPP were darker (lower L(∗)) than those made without HPP and also had lower values of a(∗) and b(∗). The addition of HPP (2.5%) significantly (P<0.05) decreased cooking losses and fracture force, and had a significant (P<0.05) inhibitory effect on lipid oxidation in cooked frankfurters. These results suggest that HPP has both antioxidant and emulsifying properties which may be of potential use in meat emulsion manufacturing.

Effect on lamb meat quality of including thyme (Thymus zygis ssp. gracilis) leaves in ewes' diet.

The aim of this study was to investigate the effect of including thyme leaves (TL) in the diet of pregnant sheep on the sensorial characteristics, bacterial spoilage and oxidative stability of lamb meat stored in modified atmosphere (70% O(2):30% CO(2)). For this, thirty-six sheep were randomly assigned to three groups: control (basal diet), T(1) (3.7% thyme leaves), T(2) (7.5% thyme leaves). Meat spoilage (TV, PSY, MY, ENT, and LA), TBARS, CIELAB coordinates, metmyoglobin and the sensory characteristics of fresh lamb meat were analyzed on days 0, 7, 14 and 21. The presence of antioxidant compounds in the diet containing TL delayed (P<0.05) colour deterioration, lipid oxidation and bacterial counts, while at the same time imparting a better appearance to the fresh lamb meat. In general, this effect was more pronounced at the higher level of TL (7.5%). High Pearsons correlation coefficients were found between the sensory attributes, CIELAB coordinates and TBARS.

Microbial, physical–chemical and sensory spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method

The aim was to study spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method. Samples were packaged under vacuum into polyamide-polypropylene pouches, cooked at an oven temperature/time of 70°C/12h, chilled at 3°C and stored at 2°C for 0, 5 or 10 weeks. Microbial (psychrotrophs, lactic acid bacteria, Enterobacteriaceae, moulds and yeasts), physical-chemical (pH, water activity, TBARS, acidity, L(∗)a(∗)b(∗) colour, texture profile analysis and shear force) and sensory (appearance, odour, flavour, texture and acceptance) parameters were determined. The results showed that sensory spoilage preceded microbiological spoilage of sous vide pork loin. Counts bellow 1logcfu/g of psychrotrophs, anaerobic psychrotrophs, Enterobacteriaceae and lactic acid bacteria were detected in any control week, while moderate counts (2-3logcfu/g) of moulds and yeasts were found. Minor changes in water activity, lipid oxidation, CIELab colour, hardness, cohesiveness or gumminess were associated with spoilage of pork loin, only decreases of lactic acid, springiness and shear force were observed. The pork loin was unacceptable after 10 weeks. This loss of acceptance was mainly due to the deterioration of meaty flavour and odour, although the loss of appearance, juiciness and firmness also contributed. Moderate warmed-over and rancidity were detected. The sensory analysis was the most effective method for determining the shelf life of the sous vide pork-based dishes.

A Comparative Study of the Characteristics of French Fries Produced by Deep Fat Frying and Air Frying

Air frying is being projected as an alternative to deep fat frying for producing snacks such as French fries. In air frying, the raw potato sections are essentially heated in hot air containing fine oil droplets, which dehydrates the potato and attempts to impart the characteristics of traditionally produced French fries, but with a substantially lower level of fat absorbed in the product. The aim of this research is to compare: (1) the process dynamics of air frying with conventional deep fat frying under otherwise similar operating conditions, and (2) the products formed by the 2 processes in terms of color, texture, microstructure, calorimetric properties, and sensory characteristics. Although, air frying produced products with a substantially lower fat content but with similar moisture contents and color characteristics, it required much longer processing times, typically 21 min in relation to 9 min in the case of deep fat frying. The slower evolution of temperature also resulted in lower rates of moisture loss and color development reactions. Differential scanning calorimetry (DSC) studies revealed that the extent of starch gelatinization was also lower in the case of air fried product. In addition, the 2 types of frying also resulted in products having significantly different texture and sensory characteristics.

Natural extracts versus sodium ascorbate to extend the shelf life of meat-based ready-to-eat meals

The effect of grape seed and green tea extracts was compared with effect of sodium ascorbate on bacterial spoilage, lipid stability and sensory quality in cooked pork meatballs during refrigerated storage. Meatballs were stored at 4 ℃ in aerobic packaging for 0, 4, 8, 12 and 16 days under retail display conditions. Lipid oxidation was evaluated as thiobarbituric acid reactive substances, volatile compounds and cholesterol oxidation products. Colour stability was assessed through CIELab parameters. Microbiological spoilage was determined through total viable, mould and yeast and coliform counts. The samples containing green tea and grape seed extracts showed lower levels of thiobarbituric acid reacting substances, major volatile compounds and microbiological counts than the samples with sodium ascorbate. Formation of cholesterol oxidation products was also inhibited to a greater extent. Colour of meatballs and pork meatballs was not affected by refrigerated storage; however, the addition of extracts provided brown shades. The addition of antioxidants did not modify the sensory attributes except for the colour. Green tea and grape seed extracts were more effective than sodium ascorbate at preventing lipid oxidation.

Determination of Shelf Life of Sous Vide Salmon (Salmo Salard) Based on Sensory Attributes

Sous vide technology permits precooked dishes of high sensory and nutritional quality to be obtained with a longer shelf life than is possible using other cooking-cooling methods. Salmon portions (200 g; 0.5, w:w; greased with olive oil) were par-roasted (300 degrees C/3 min), cooked using sous vide technology (80 degrees C/43 min), and maintained in anaerobic conditions at 2 degrees C for 0, 4, 8, 12, 15, 18, 22, and 25 d. At each control day, Enterobacteriaceae counts were made and the attributes of sensory spoilage were determined (3 visual, 2 odor, 2 flavor, and 3 texture attributes) by a panel of trained judges. A loss of smell, taste, color, and juiciness was detected during storage, along with the appearance of off-odors and off-flavors. The shelf life of the sous vide salmon based on sensory analysis was established at 18 d.

Spoilage of sous vide cooked salmon (Salmo salar) stored under refrigeration.

The spoilage of Sous Vide ‘SV’ cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide—polypropylene pouches, cooked at an oven temperature/time of 80 °C/45 min, quickly chilled at 3 °C and stored at 2 °C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical—chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical—chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

Influence of Pre-Slaughter Process on Pork Quality: An Overview

Handling practices prior to slaughter have significant influence in the stress level and animal welfare of pigs, and consequently, in the final meat quality. This paper reviews current knowledge about ante mortem factors (fasting period, farm handling, mixing, loading, unloading, transport, lairage conditions, and driving to the stunner) related to the live animal that influence pork quality with special emphasis on technological quality attributes. The development in slaughter technologies and their practical applications in pig slaughterhouses are described. In spite of genetic effects and slaughter techniques, poor pre-slaughter operations lead frequently to an increase of physiological and physical stress in pigs. Ante mortem factors, such as lairage time or moving pigs into the slaughter rooms, and inadequate design of slaughterhouse facilities have an important effect on pig stress, affecting meat quality after slaughter. Some recommendations to guarantee animal welfare and obtain the best meat quality are reviewed.