Effect of an edible crosslinked coating and two types of packaging on antioxidant capacity of castilla blackberries

In order to increase the shelf life and maintain the quality and stability of the biological compounds with antioxidant activity present in Castilla blackberry fruits, a sodium alginate-based edible crosslinked coating was applied, and the fruits were packed in two different plastic containers and stored under refrigeration (3 ± 1 °C). Total antioxidant capacity and its relationship to physicochemical variables such as pH, Brix, and acidity were evaluated in six treatments: uncoated blackberry stored in a macroperforated container (T1) and thermosealed container (T2), without crosslinked coating in a macroperforated container (T3) and thermosealed container (T4), with crosslinked coating (calcium ions) packed in macroperforated container (T5) and thermosealed container (T6). The results indicated that factors such as gas permeability in the coatings, the packaging used, and physicochemical parameters significantly affected the fruit total antioxidant capacity, with the highest level in T1 (0.22 µgEAA/ml) at the end of the essay, which is related to the lowest levels of pH and direct exposure to air. On the other hand, the lowest value was obtained in T6 (0.16 µgEAA/ml) due to the crosslinked coating, packaging in the thermosealed container, and higher pH value. Variations in acidity, Brix, and pH indicate the presence of degenerative processes in the crosslinked coating treatments, which limited the physicochemical changes.

Processing of chopped mussel meat in retort pouch

Abstract Chopped mussel meat packaged in retort pouches was processed in a laboratory-scale water immersion retort, adapted for processing under overpressure conditions. Retort temperature effects on product yield and on cook value were evaluated by setting the F0 at 7 min. The effects of different pre-treatments (salting and marination) on the characteristics of mussels were evaluated after processing at retort temperature of 118 °C and during a whole year of storage at 25 °C. The salted samples showed better yield during storage, while no differences were found for the other physicochemical parameters.

Physicochemical and microbiological parameters of dried salted pork meat with different sodium chloride levels

The objective of this study was to evaluate the physicochemical and microbiological parameters of pork meat submitted to dry salting. Sodium chloride (NaCl) was added at levels of 0%, 2.5%, 5%, 7.5% or 10% by the meat weight. Dry salting technique was used, which consists of rubbing the sodium chloride manually, followed by a rest period. The data were submitted to analysis of variance using a completely randomized experimental design. The means were compared by Duncan test at 5%. The salting process reduced (P < 0.05) humidity and water activity, and it increased (P < 0.05) ash, chloride, palmitic acid, and water holding capacity levels compared to those of the control. Luminosity (L*) was lower (P < 0.05) in the control, and a* color was more intense in samples with 2.5% NaCl. Cooking loss was lower (P < 0.05) in the samples salted with 5% and 10% NaCl, and similarity was observed between the levels 0 and 7.5% salt. The treatments with levels 0% and 2.5% NaCl had higher mesophilic counts. The other microbiological parameters were within limits established by law. Therefore, salting with 5% NaCl can be used in pork meat in order to maintain the physicochemical and microbiological characteristics of the final product.

Physicochemical properties and antioxidant capacity of propolis of stingless bees (Meliponinae) and Apisfrom two regions of Tocantins, Brazil

ABSTRACTThe composition of propolis depends on time, vegetation and the location of the collection area. The objective of this study was to determine the physicochemical characteristics, the concentration of phenol compounds and the antioxidant capacity of propolis of native stingless bees (Meliponinae)and Apis from the State of Tocantins. Extraction with 80% ethanol (v/v) was performed in order to obtain the extracts. Parameters examined were: propolis mass loss by desiccation at 105 ºC, ashes, wax concentration and pH. Furthermore, the propolis antioxidant activity was measured, as well as the total concentration of phenol compounds. The extracts were also analyzed by high performance liquid chromatography. The total concentration of phenol compounds varied between 121.78 and 631.29 (mg GAE g-1). The antioxidant activity expressed by the value of CE50 varied between 29.81 and 845.38 µg mL-1. High performance liquid chromatography analysis allowed us to infer the existence of phenol compounds. The results indicated that the studied propolis samples constitute good sources of natural antioxidants. The variety of phenol compounds identified in this study, and the diverse biological functions reported in literature for these compounds indicated that this stingless bee propolis (Meliponinae) and Apis has a high pharmacological potential.

Physicochemical characterization and antioxidant capacity of pitanga fruits (Eugenia uniflora L.)

This study was carried out to obtain more information about the physicochemical properties, composition, and antioxidant activity of pitanga fruits (Eugenia uniflora L.), particularly fruits from the State of Rio Grande do Sul, Brazil. Pitanga with different flesh colors (purple, red, and orange) from tree selections cultivated at Embrapa Clima Temperado (RS-Brazil) were analyzed. Only slight differences were observed in the quality parameters and in the proximate and fatty acid compositions among the fruits studied. The extracts from purple-fleshed pitanga had the highest total phenolic and anthocyanin contents along with the highest antioxidant capacity. The antioxidant capacity (DPPH and FRAP assays) of methanolic pitanga extracts was highly correlated with the total phenolic content, but in ethanolic extracts, the anthocyanin content was correlated only with the FRAP antioxidant capacity. Orange fleshed pitanga had higher β-cryptoxanthin and β-carotene levels than those of the red fruit, which had higher lycopene content. The results indicate that the purple-fleshed pitanga, cultivated in Rio Grande do Sul, is a rich source of phenolic compounds and has high antioxidant capacity. The red and orange-fleshed pitanga, on the other hand, are rich sources of carotenoids.

Evaluation of process parameters in the industrial scale production of fish nuggets

This work reports the use of experimental design for the assessment of the effects of process parameters on the production of fish nuggets in an industrial scale environment. The effect of independent factors on the physicochemical and microbiological parameters was investigated through a full 24 experimental design. The studied factors included the temperature of fish fillet and pulp in the mixer, the temperature of the added fat, the temperature of water and the ratio of protein extraction time to emulsion time. The physicochemical analyses showed that the higher temperature of the pulp and fillet of fish, the lower the protein in the final product. Microbiological analyses revealed that the counting of Staphylococcus coagulase positive, total and thermo-tolerant coliforms were in accordance with the current legislation.

Physicochemical characteristics of organic honey samples of africanized honeybees from Parana River islands

This research was carried out to evaluate the physicochemical composition of organic honey in Paraná River islands, in Porto Brasílio, State of Paraná. Honey was harvested directly from super of the colonies in three apiaries spread in the Floresta and Laranjeira Islands, from August 2005 to August 2006. Twenty-four samples of organic honey produced by Africanized honeybees were evaluated. The following parameters were analyzed: pH, acidity, formol index, hydroxymethylfurfural, ashes, color, electric conductivity and moisture. Three replications per sample were performed for laboratorial analysis, giving the means and standard deviation. Most honey samples were in conformity with the Normative Instruction 11 from October 20, 2000. However, 4.17% were not in accordance with the moisture standards, 8.33% showed high concentrations of hydroxymethylfurfural, thus, totalizing 12.50% of non-complying samples. Nevertheless, 87.50% of the analyzed honey samples are within the standards, being characterized as an organic product of excellent quality, with good commercialization perspectives in the market.

Influence of the fungi population on the physicochemical and chemical composition of coffee (Coffea arabica L.)

The influence of fungi associated with coffee fruits was verified regarding the chemical and physicochemical composition of Coffea arabica L. raw grains. The fruits were harvested at EPAMIG Experimental farm in Lavras, State of Minas Gerais - making up the different samples here analyzed. After processing and drying, the grains were incubated in wet chamber for fungal exteriorization through the blotter test method and submitted to the following analyses: polyphenoloxidase, total reducing and non-reducing sugars, clorogenic acid, titrable acidity, potassium leaching, electric conductivity and caffeine. The occurrence of the P. variable, P. rugulosum, P. funiculosum, F. equiseti, F. semitectum, A.alutaceus, A. niger and C. cladosporioides fungi in the different samples was detected. From the analysis of the results obtained, it was observed that the presence of the Aspergillus alutaceus fungus reduces the activity of the enzyme polyphenoloxidase and increases the values of potassium leaching, electric conductivity and chlorogenic acid. The incidence of the Cladosporium cladosporioides fungus influenced the average values of potassium leaching and electric conductivity.

Microbiological and physicochemical characterization of surimi obtained from waste of piramutaba fillet

The aim of this work was to perform the microbiological and physicochemical characterization of surimi made from waste of piramutaba filleting. The results of physicochemical characterization of the waste and surimi were: moisture (76.37 and 79.11%), total lipids (5.35 and 0.74%), proteins (14.92 and 10.79%), ash (3.03 and 2.35%), pH (6.9 and 7.4), caloric value (109.15 and 77.86 kcal.g-1), and water activity (both 0.98), respectively. The results of the levels of total volatile bases were 7.29 mgN/100-1 g (waste) and 7.01% carbohydrate (surimi). The values of total lipids and proteins were reduced during the preparation of surimi, probably due to successive washes during the processing. Waste and surimi were examined microbiologically and are in compliance with required parameters. The results show a loss of red (a* parameter) and yellow (b* parameter) color. On the other hand, the L* parameter (lightness) increased after the processing of surimi. It can be concluded that piramutaba waste can be used for surimi preparation and as a source of nutrients for human consumption, providing an alternative use of these wastes avoiding their disposal polluting the environment.

Physicochemical and sensory profile of rice bran roasted in microwave

The purpose of this study was to evaluate the physical, chemical, and sensory changes in bran from three rice cultivars according to microwave roasting time. This study analyzed three rice cultivars, BRS Sertaneja (S), BRS Primavera (P), and IRGA 417 (I) determining the color parameters (L*, a*, and b *) at 6, 9, 12, 15, and 18 minutes of roasting time. After applying the difference from control test, the rice brans with different characteristics aroma and flavor were selected: S and P roasted for 9 and 15 minutes and IRGA 417 roasted for 9, 12, and 15 minutes. These samples were characterized by Free-Choice Profile descriptive sensory analysis, and their chemical composition was also determined. The longer the roasting process, the higher the roasted flavor intensity and aroma. The IRG 417 cultivar roasted for 12 minutes showed a sweeter flavor and aroma. After roasting, the brans remained rich in protein and lipid and presented higher fiber content and lower reducing sugar and phytic acid content. Microwave roasting for 12 minutes can be a viable option for improving the sensory functional and nutritional characteristics of the rice bran considering its use in food products.

Genetic diversity and comparison of physicochemical and nutritional characteristics of six quinoa (Chenopodium quinoa willd.) genotypes cultivated in Chile

The present study was focused on the analysis of agronomical, nutritional, physicochemical, and antioxidant properties of six genetically different quinoa (Chenopodium quinoa Willd) genotypes cultivated in three distinctive geographical zones of Chile. Ancovinto and Cancosa genotypes from the northern Altiplano (19 ºS), Cáhuil and Faro from the central region (34 ºS), and Regalona and Villarica from the southern region (39 ºS) are representative of high genetic differentiation among the pooled samples, in particular between Altiplano and the central-southern groups. A Common-Garden Assay at 30 ºS showed significant differences among seed origins in all morphometric parameters and also in yields. Altiplano genotypes had larger panicule length but no seed production. A significant influence of the different quinoa genotypes on chemical composition and functional properties was also observed. Protein concentration ranged from 11.13 to 16.18 g.100 g-1 d.m., while total dietary fiber content ranged from 8.07-12.08 g.100 g-1 d.m., and both were the highest in Villarrica ecotype. An adequate balance of essential amino acids was also observed. Sucrose was the predominant sugar in all genotypes. Antioxidant activity was high in all genotypes, and it was highest in Faro genotype (79.58% inhibition).

Estimate of respiration rate and physicochemical changes of fresh-cut apples stored under different temperatures

In this study, the influence of storage temperature and passive modified packaging (PMP) on the respiration rate and physicochemical properties of fresh-cut Gala apples (Malus domestica B.) was investigated. The samples were packed in flexible multilayer bags and stored at 2 °C, 5 °C, and 7 °C for eleven days. Respiration rate as a function of CO2 and O2 concentrations was determined using gas chromatography. The inhibition parameters were estimated using a mathematical model based on Michaelis-Menten equation. The following physicochemical properties were evaluated: total soluble solids, pH, titratable acidity, and reducing sugars. At 2 °C, the maximum respiration rate was observed after 150 hours. At 5 °C and 7 °C the maximum respiration rates were observed after 100 and 50 hours of storage, respectively. The inhibition model results obtained showed a clear effect of CO2 on O2 consumption. The soluble solids decreased, although not significantly, during storage at the three temperatures studied. Reducing sugars and titratable acidity decreased during storage and the pH increased. These results indicate that the respiration rate influenced the physicochemical properties.

Physicochemical and microbiological evaluation of corrientes artisanal cheese during ripening

The aim of this study was to evaluate some physical and chemical parameters (total solids, pH, acidity, fat, acid degree value of fat, salt, protein and nitrogen fractions) and their effects on the beneficial (lactic acid bacteria: LAB) and undesirable microbial populations (coliforms, Escherichia coli, Staphylococcus aureus, moulds, and yeast) during ripening of Artisanal Corrientes Cheese, an Argentinian cow's milk variety, to determine whether a longer ripening period than usual improve its hygienic-sanitary quality. The protein content was much higher than that of other cow's milk cheeses with similar values of fat. The larger peptides showed values three times higher in the 30 day-old cheese than those obtained in the beginning of the process. Staphylococcus aureus and Escherichia coli were detected (3.04 ± 1.48 log10 cfu/g of cheese, 2.21 ± 0.84 log10 MPN/g of cheese) even at 15 and 30 days of ripening, respectively. The distribution of three hundred LAB strains classified to the genus level (lactococci:lactobacilli:leuconostocs) was maintained during the ripening period. The high number of LAB in rennet may have contributed to the fermentation as a natural whey starter, unknown source of LAB for this specific cheese so far. The physicochemical changes that occur during ripening were not big enough to inhibit the growth of undesirable microorganisms.

Changes in the physicochemical and microbiological properties of frozen araça pulp during storage

Araça belongs to the Myrtaceae family and is popularly known as araçá-comum, araçá-azedo, or araçá-do-campo. Frozen fruit pulp is of great importance for the food industry, which can produce it at the time of harvest, store it, and use it according to the demand of the consumer market and/or as an ingredient in the formulation of products such as yogurt, candies, and ice creams among others. The aim of this study was to evaluate the physical, chemical, and microbiological stability of frozen araça pulp during 12 months of frozen storage. It was observed that the levels of moisture (90.55-88.75%), ash (0.34-0.26%) total soluble sugars (7.11-6.62%), sucrose (3.55-1.39%), soluble pectin (0.24-0.23%), total pectin (0.5-0.46%), pH (3.82-2.31%), organic acids (698.12-122.25 µg.g-1 citric acid), and phenolic compounds (6.22-0.00 mg GAE.100 g-1) decreased during storage, whereas the levels of protein (0.61-0.83%), lipids (0.14-0.38%), total carbohydrates (8.36-9.78%), calorific value (37.14-45.86 kcal.100 g-1), reducing sugars (3.51-5.21%), soluble solids (5.17-6.0%), total antioxidant capacity (6.89-35.13%), and color parameters (L*49.75-50.67; a*0.79-1.82 and b*22.5-25.19) increased over the one-year storage period. According to the chemical and microbiological parameters assessed, the product can be stored for 12 months without loss of quality with addition of citric acid as a preservative.

Hydration kinetics, physicochemical composition, and textural changes of transgenic corn kernels of flint, semi-flint, and dent varieties

The hydration kinetics of transgenic corn types flint DKB 245PRO, semi-flint DKB 390PRO, and dent DKB 240PRO was studied at temperatures of 30, 40, 50, and 67 °C. The concentrated parameters model was used, and it fits the experimental data well for all three cultivars. The chemical composition of the corn kernels was also evaluated. The corn cultivar influenced the initial rate of absorption and the water equilibrium concentration, and the dent corn absorbed more water than the other cultivars at the four temperatures analyzed. The effect of hydration on the kernel texture was also studied, and it was observed that there was no significant difference in the deformation force required for all three corn types analyzed with longer hydration period.