Effect of a new emulsifier containing sodium stearoyl-2-lactylate and carrageenan on the functionality of meat emulsion systems.

The emulsion capacity and stability of a new emulsifier containing sodium stearoyl lactylate plus iota carrageenan (SSL/iC) in comparison to caseinate and soy isolate was analysed. The emulsion capacity and stability of SSL/iC in oil/water (O/W) model system emulsions was higher than shown by caseinate and soy isolate. However, the O/W emulsion stability was negatively affected by sodium chloride addition, but positively affected by an increase in temperature. Meat batters were made with caseinate, soy isolate, and SSL/iC at the minimum concentration that showed a good performance (>75% stability) in the O/W emulsions. The emulsifier SSL/iC produced high cook yields and good stability when used in meat batters. However, the cooked meat batters containing SSL/iC showed texture characteristics highly detrimental to the sensory analysis. On the other hand, the addition of 2% potato starch reduced the differences in texture parameters among the samples made with the different emulsifiers.

Effect of lyophilization on the mechanical characteristics of a large particle and on the behavior of immobilized bacterial spores.

The mechanical stability of the carrier and the behavior of the sensor element of a time-temperature integrator (TTI) after lyophilization and storage for 60 days at room temperature were studied. The results indicated that particles containing added starch at concentrations from 2 to 12% had good handling characteristics for use as TTI carriers, although mechanical resistance was lower by comparison with freshly prepared particles. Lyophilization reduced the number of viable microorganisms by 17 to 25%, depending on the length of the storage period. Variations were also observed in the count of surviving microorganisms after heating at 121 degrees C for 12 min. These variations, expressed as decimal reductions in the number of microorganisms, might reflect an effect of lyophilization on the thermal resistance of the immobilized spores.

Postmortem meat quality and sex affect textural properties and protein breakdown of dry-cured ham.

Texture measurements by instrumental texture profile analysis (TPA) and protein degradation analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) were performed on 30 dry-cured hams resulting from four different post-mortem meat qualities categories (PSE, RSE, RFN and DFD). The main differences were observed in dry-cured hams from PSE and RFN meat qualities. Penetration force (80%), hardness, springiness, cohesiveness and chewiness, were significantly lower (P<0.05) in PSE than in RFN quality classes. The rate of the ripening process was affected as a higher proteolysis and absence of fragments at 150 and 85 KDa in PSE in relation to RFN classes, and with an intermediate proteolysis of RSE and DFD classes. The effect of sex was observed as a significant (P<0.05) low hardness in the hams obtained from female pigs. The duration of the ripening, for a better uniformity in dry-cured ham production, should be adapted to the initial pH and to drip loss parameters of the raw material.

High hydrostatic pressure treatment provides persimmon good characteristics to formulate milk-based beverages with enhanced functionality.

High hydrostatic pressure (HHP) applied during food processing can improve the retention of food quality attributes and nutritional values in comparison with pasteurization. Persimmon is a good source of bioactive compounds but it is a seasonal fruit that cannot be consumed throughout the year. The aim of this work was to compare the HHP and pasteurization treatments to formulate milk-based beverages containing this carotenoid rich ingredient and to evaluate their performance in these beverages. The carotenoid and tannin contents of persimmon were determined and the microstructure and rheology of the new milk-based persimmon beverages were examined. The results showed that HHP treatment favoured the release of carotenoids from the fruit matrix and precipitation of the tannins. The milk-based beverages prepared with the high-pressure persimmon presented the best rheological properties because unlike the untreated and pasteurized persimmon milk-based beverages, they did not form a gel-like structure or separate out.

Sensory properties determined by starch type in white sauces: effects of freeze/thaw and hydrocolloid addition.

The effect of 5 types of starch (rice, potato, waxy corn, corn, and modified waxy corn) on the sensory properties of white sauces was studied. A comparative study was also made of variations resulting from freezing/thawing and effect of replacing 0.15% starch with 2 nonstarchy hydrocolloids, xanthan gum (XG), or locust bean gum (LBG) in samples to be frozen. The sensory properties were studied through descriptive analysis by a panel of 10 trained judges. Principal components analysis and cluster analysis were used to group each of the samples according to the scores for consistency, resilience, graininess, thickness, heterogeneity, creaminess, and mouth coating, the sensory attributes which were chosen to define the sauces under study. Significant differences were found between the different starches employed: the rice and modified starches presented similar behavior to each other, as did the potato starch and corn starch, while the waxy starch sauce stood apart from the rest because of its resilience. The freeze/thaw cycle had the greatest effect on the corn-starch sauce, increasing its graininess and heterogeneity values owing to retrogradation. Adding XG or LBG to the sauces subjected to a period of freezing/thawing did not have a significant effect on the sensory attributes of the reheated sauces made with rice, potato, or waxy or modified starch, but lower graininess and heterogeneity values were observed in the sauce made with corn starch.

Textural and sensory characteristics of whole and skimmed flavored set-type yogurt during long storage.

A study of refrigerated storage (10 degrees C for 91 d) of whole and skimmed flavored set-type yogurt was made. Comparison with storage at 20 degrees C for 21 d and 30 degrees C for 3 d (accelerated) was also carried out. Refrigerated storage yogurts were assessed by a trained panel and by a consumer panel. Trained-panel scores were correlated to instrumental data, and the acceptability data for long storage were studied using consumer criteria. In all cases, after-storage pH values barely changed over storage time, indicating that the yogurt samples did not develop much acidity under any of the storage conditions studied. The profile of the instrumental texture curves obtained corresponded to a firm gel, which broke after a plunger penetrated the sample, and the firmness values of the whole yogurt were lower than for the skimmed yogurt under all the storage conditions studied. From a microbiological point of view, the viability of the yogurts was adequate at the different storage times and temperatures studied, although those stored at 10 degrees C for long periods would not comply with some countries' minimum requirements. Logistic regression of the data from a 50-consumer sensory evaluation showed that the probability of the whole yogurt being accepted after 91 d storage at 10 degrees C was around 40%, whereas for the skimmed yogurt it was only 15%, largely because the skimmed yogurt developed certain negative attributes at an earlier stage of storage than the whole yogurt.