Antibiotic residues in Brazilian UHT milk: a screening study

The aim of this research was to carry out a screening study to check the incidence of antimicrobial residues in Brazilian UHT milk according to rapid yoghurt method. Of the 100 (100%) samples analysed, 96 (96%) showed no traces of antibiotic residues while 4 (4%) indicated probable presence of antibiotic residues. The results suggest that the Brazilian Sanitary Surveillance Agency should apply continuous monitoring programs in order to obtain a safe product offering no health risks to consumers.

Soy and Brazil nut beverage: processing, composition, sensory, and color evaluation

Despite its high nutritional value, soymilk consumption in Western countries is limited mainly due to undesirable flavors developed during the traditional elaboration process. Brazil nut (Bertholletia excelsa) has pleasant flavor and recognized nutritional value. Thus, the aim of this work was to elaborate a soy and Brazil nut beverage exploring the use of two national products of high nutritional quality. The process for manufacturing a soy and Brazil nut beverage consisted of elaboration, formulation, and homogenization of soymilk and Brazil nut milk. The addition of five levels (10, 20, 30, 40, and 50%) of Brazil nut milk to soy beverages was investigated. Although no significant differences in consumer average preference (p > 0.05) were observed among the beverages, analyzing both the consumer preference frequency distribution of the products and the Internal Preference Mapping (IPM), it was possible to conclude that the beverage with 30% of Brazil nut milk reached the most adequate performance demonstrating the sensory benefits Brazil nuts brought to the product. Regarding proximate composition, it did not present a better performance in terms of nutritional value, except for the oil content. The soy and Brazil nut beverage presented visual stability and no phase separation despite the non-stability shown by Brazil nut beverage itself. When Brazil nut milk was added to soy beverage, the final product became whiter than soy beverage, which is appealing to consumers who normally search for a clearer soymilk. The soy and Brazil nut beverage processing can be considered an alternative to increase the use of Brazil nuts in the Brazilian diet.

Obtention and characterization of gluten-free baked products

This work had as objective the development of gluten-free breads and muffins using rice flour and maize and cassava starches. From seven samples resulting from a Simplex-Centroid design, the sensory and instrumental analyses of specific volume, elasticity, and firmness were performed. For the sensory analysis, the optimized formulation contained 50% of rice flour and 50% of cassava starch, and for the instrumental evaluation, the optimal simultaneous point for the three conducted analyses were 20% of rice flour, 30% of cassava starch, and 50% of maize starch. A comparative analysis of specific volume, elasticity, firmness, and triangular test was performed with pre-baked, baked, and frozen bread. Physicochemical, nutritional, and microbiological analyses were performed for both bread and muffin according to the Brazilian legislation.

Application of Response Surface Methodology to study the effect of different calcium sources in fish muscle-alginate restructured products

Sodium alginate needs the presence of calcium ions to gelify. For this reason, the contribution of the calcium source in a fish muscle mince added by sodium alginate, makes gelification possible, resulting a restructured fish product. The three different calcium sources considered were: Calcium Chloride (CC); Calcium Caseinate (CCa); and Calcium lactate (CLa). Several physical properties were analyzed, including mechanical properties, colour and cooking loss. Response Surface Methodology (RSM) was used to determine the contribution of different calcium sources to a restructured fish muscle. The calcium source that modifies the system the most is CC. A combination of CC and sodium alginate weakened mechanical properties as reflected in the negative linear contribution of sodium alginate. Moreover, CC by itself increased lightness and cooking loss. The mechanical properties of restructured fish muscle elaborated were enhanced by using CCa and sodium alginate, as reflected in the negative linear contribution of sodium alginate. Also, CCa increased cooking loss. The role of CLa combined with sodium alginate was not so pronounced in the system discussed here.

Density and rheological parameters of goat milk

The rheological behavior and density of goat milk was studied as a function of solids concentration (10.5 to 50.0%) and temperature (273 to 331 k). Newtonian behavior was observed for values of total solids (TS) between 10.5 and 22.0% and temperatures from 276 to 331 k changing to pseudoplastic behavior without yield stress for TS from 25.0 to 39.4% at the same range of temperature. Goat milk with TS between 44.3 to 50.0% and temperatures of 273 to 296 k showed yield stress in addition to pseudoplastic behavior. At 303 to 331 k the power law model was observed again, without yield stress. The density of goat milk ranged from 991.7 to 1232.4 kg.m-3.

Modeling of allergen proteins found in sea food products

Shellfish are a source of food allergens, and their consumption is the cause of severe allergic reactions in humans. Tropomyosins, a family of muscle proteins, have been identified as the major allergens in shellfish and mollusks species. Nevertheless, few experimentally determined three-dimensional structures are available in the Protein Data Base (PDB). In this study, 3D models of several homologous of tropomyosins present in marine shellfish and mollusk species (Chaf 1, Met e1, Hom a1, Per v1, and Pen a1) were constructed, validated, and their immunoglobulin E binding epitopes were identified using bioinformatics tools. All protein models for these allergens consisted of long alpha-helices. Chaf 1, Met e1, and Hom a1 had six conserved regions with sequence similarities to known epitopes, whereas Per v1 and Pen a1 contained only one. Lipophilic potentials of identified epitopes revealed a high propensity of hydrophobic amino acids in the immunoglobulin E binding site. This information could be useful to design tropomyosin-specific immunotherapy for sea food allergies.

Antioxidants in yacon products and effect of long term storage

Yacon (Smallanthus sonchifolius (Poepp. and Endl.) H. Robinson) is a storage root originally grown in the Andean highlands. The fresh roots are perishable and quickly turn brown during handling and processing. Aiming to prolong shelf-life and to preserve the antioxidant compounds in yacon roots, 3 mm thick yacon slices were dried in a drying cabinet at 40, 50, and 60 ºC to a moisture content of 10-14%, and yacon strips were sun dried to a moisture content of 15-20%. The total phenolic content was measured by the Folin-Ciocalteu method, and the quenching capacity was evaluated by measuring the amount of DPPH (1,1-diphenyl-2-pidrylhydrazyl) inhibited in samples after drying and after 7 months of storage. The results showed that it is possible to preserve the antioxidant capacity in yacon after cabinet or sun drying. Both yacon chips and strips presented total phenolic content values similar to those of fresh yacon roots. Both products also showed a high inhibition capacity of DPPH (1,1-diphenyl-2-pidrylhydrazyl). A significant decrease in the phenolic content was observed in the yacon chips after storage, which indicates that the sun dried strips are more suitable for storage.

"Petit suisse" cheese from kefir: an alternative dessert with microorganisms of probiotic activity

"Petit Suisse" is a creamy cheese. Kefir is a symbiotic mixture of lactic acid bacteria and yeasts with probiotic activity including immunomodulation and balance of intestinal microflora. The present study aims to develop "Petit Suisse" cheese from kefir. Kefir grains were grown in pasteurized cow milk, and after the separation of kefir the serum was discarded and the "Petit Suisse" cheese was prepared using strawberry, mangaba, herbs, and dried tomatoes. The acceptance of the different preparations was evaluated using a nine-point hedonic scale followed by ANOVA. The sweet and salty products were compared by the Student's t-test. Purchase intent was evaluated by the means test and frequency distribution. All products were well accepted by the judges. The product was characterized by low yield, but it can be prepared at home at low cost. The nutritional composition analyses and the variety of flavors as well as the range of age of the judges are alternatives for further studies.

Rosemary extract and celery-based products used as natural quality enhancers for colonial type salami with different ripening times

This study aimed to evaluate the use of rosemary (Rosmarinus officinalis) extract (RE), celery (Apium graveolis), and low levels of NO3 and NO2 as natural agents to enhance the quality of colonial salami. Salami was produced according to three treatments: (A) Control: 0.1% curing salt; (B) Rosemary: 0.05% curing salt + 0.5% RE (rosemary extract); and (C) Rosemary+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery) + 0.5% of RE (rosemary extract). There was no effect (P > 0.05) of the treatments on water activity, Na content, and residual NO3 and NO2. Fatty acids C18:2 and C20:4 were reduced (P < 0.05) during the ripening period in the Control treatment indicating possible oxidation. The use of celery resulted in lower pH values (P < 0.05) in the salami. Reduced addition of NO3 and NO2 resulted in salami lighter in color (higher L* values, P < 0.05) at the 12th day of ripening. In conclusion, celery-based products proved to be an effective source of NO2 and NO3 for color development, but the low pH of the product indicates the need for better evaluation of its use in fermented salami. The RE (rosemary extract) reduced fat oxidation in salami, but this needs further evaluation.

Deep-fat frying of meat products in palm olein

This study investigated the discontinuous frying of breaded meat products in palm olein in a 28 L-electric fryer maintained at 182 ºC for 8 hours a day. Three 400-500 g batches of meat products were fried for 4.5 minutes daily. For comparison purpose, thermoxidation tests were performed using inert material with added moisture and without the addition of f ood (heating only). The total polar compound content did not reach the 25% limit, and nor did the formation of polymerized products exceed 5%, which indicates the good frying performance of palm olein for frying. Other analytical parameters and rapid tests were also evaluated. The sensory attributes, such as odor, colour, and foam formation determined when the frying oils should be discarded. The addition of water to the inert material contributed to the final value of 1.00 ± 0.01% (in palmitic acid), while the oil subjected only to heating reached respectively 0.26 ± 0.02%, and the oils used to fry breaded meat and breaded chicken reached 0.38 ± 0.00% and 2.35 ± 0.01%, respectively. This suggests a protective effect of the water during frying since the oil subjected only to heating was more prone to degradation.