The influence of different combinations of probiotic bacteria and fermentation temperatures on the microbiological and physicochemical characteristics of fermented lactic beverages containing soybean hydrosoluble extract during refrigerated storage

Lactic beverages containing probiotics were prepared with whole UHT milk, whey of Mozzarella cheese, soybean hydrosoluble extract and sugar. Three formulations were studied, each one containing a different combination of probiotic/starter bacteria, fermented at two different temperatures (37 and 45 °C). The aim of this work was to verify the influence of these variables on the viability of probiotic microorganisms and on the physicochemical stability of lactic beverages during storage under refrigeration (21 days at 7 °C). The results indicated that the fermentation temperature had a significant effect on the viability of probiotic bacteria. Counts for Lactobacillus acidophilus were affected by storage time, resulting appropriate after 21 days only for the beverage fermented at 37 °C. Physicochemical parameters did not exhibit drastic variations - proving the stability of formulations during storage. Cells of Bifidobacterium spp. showed high survival ability, probably due to the presence of growth promoters from soybean and cheese whey. The fermentation temperature of 37 °C allowed counts above the minimum limit for all the studied microorganisms, being preferred to the temperature of 45 °C. The inclusion of soybean hydrosoluble extract, a prebiotics source, resulted in a symbiotic product with more benefits to the health of consumers.

Chemical and physicochemical characteristics changes during passion fruit juice processing

Passion fruit is widely consumed due to its pleasant flavour and aroma acidity, and it is considered very important a source of minerals and vitamins. It is used in many products such as ice-cream, mousses and, especially, juices. However, the processing of passion fruit juice may modify the composition and biodisponibility of the bioactive compounds. Investigations of the effects of processing on nutritional components in tropical juices are scarce. Frequently, only losses of vitamin C are evaluated. The objective of this paper is to investigate how some operations of passion fruit juice processing (formulation/homogeneization/thermal treatment) affect this product's chemical and physicochemical characteristics. The results showed that the chemical and physicochemical characteristics are little affected by the processing although a reduction in vitamin C contents and anthocyanin, large quantities of carotenoids was verified even after the pasteurization stage.

Physical, chemical, technological and sensory characteristics of Frankfurter type sausage containing okara flour

The addition of okara flour to an emulsified meat product (Frankfurter type sausage) was evaluated based on the physical, chemical, technological, and sensory characteristics of the final product. Okara, residue from soymilk production, was provided by two soymilk producing companies whose production systems were based on the hot disintegration of the decorticated (company B) or undecorticated (company A) soybeans. The okara was dehydrated using a flash dryer and then ground into flour (>420 µm). However, The okara flours A and B showed approximately the same amount of protein (35 and 40 g.100 g-1 dwb). However, the okara flour A presented higher values (p < 0.05) for all technological functional properties studied (emulsification capacity, emulsion stability, protein solubility, and water hold capacity) than those of okara flour B. The A and B okara flours were used in a frankfurter sausage formulation as substitution of 1.5% and 4% of meat. The results showed that the sausages containing okara flours A and B, as well as the control sausage, were accepted by the sensory panel. Moreover, there were no significant differences (p < 0.05) in the physical (color, objective texture, and emulsion stability) and chemical (pH and proximate composition) measurements of the sausages with and without the okara flour.

Effect of starter culture and inulin addition on microbial viability, texture, and chemical characteristics of whole or skim milk Kefir

The effect of inulin addition and starters (Kefir grains or commercial starter culture) on the microbial viability, texture, and chemical characteristics of Kefir beverages prepared with whole or skim milk was evaluated during refrigerated storage. The type of starter did not influence microbial viability during the storage of the beverages, but the chemical and textural changes (decreases in pH, lactose concentration, and inulin and increased acidity, firmness, and syneresis) were more pronounced in the formulations fermented with grains than those fermented with the starter culture. The addition of inulin did not influence acidity or viability of lactic acid bacteria, but in general, its effect on the survival of acetic acid bacteria, Lactococcus and yeasts, firmness, and syneresis depended on the type of milk and starter culture used. Generally, the yeast, acetic acid bacteria, and Leuconostoc counts increased or remained unchanged, while the total population of lactic acid bacteria and Lactococcus were either reduced by 1 to 2 logs or remained unchanged during storage.

Soymilk plain beverages: correlation between acceptability and physical and chemical characteristics

The objective of the research was to relate the physical and chemical characteristics of soymilk plain beverages to its sensory acceptance. Five commercial products and a new product formulated based on the less accepted sample were used. The overall acceptance was evaluated by 102 assessors using a 10-point hybrid hedonic scale. The hedonic scores ranged from 3.8 (sample E) to 7.0 (A). Most assessors (55%) preferred sample A, which was viscous (26.6 cp), dark (L* = 77.7), and slightly acidic (pH = 6.6). Sample C, which had lower solid content and higher acidity, was preferred by 29% of the assessors. These two beverages showed the greatest commercial potential of the products analyzed. The least-accepted sample (E), preferred by 8% of the assessors, had a lighter color (L* = 96.8), lower viscosity (13.5 cp), higher lipid content (2.2 g/100 g), and less protein (1.68 g/100 g) than the other products evaluated. A reformulation of the least preferred product (E) with the addition of maltodextrin and also vanilla and milk flavors increased its acceptance, yielding an average score of 7.2. Overall, it was observed that a soymilk plain beverage with higher viscosity, darker color, and higher protein content best meets consumer expectations.

Effect of treatment with adsorbent resin on the volatile profile and physicochemical characteristics of clarified cashew apple juice

Increased preference for healthy and functional foods could be an opportunity to increase the consumption of clarified cashew apple juice. Given its level of fructose, glucose, and vitamin C, it can be used as a base in blends. However, its characteristic odor can interfere with the acceptance of these formulations, especially by consumers who are not familiar with cashew aroma. The aim of this study was to evaluate the effect of treatment with macroporous resins (FPA54, FPX66, XAD761, and XAD4) on the volatile profile and physicochemical characteristics of clarified cashew apple juice. After the treatment with the resins, the volatile profile was evaluated using solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS). The physicochemical analyses performed were: pH, soluble solids (ºBrix), total titrable acidity, reducing sugars, and vitamin C. Gas chromatography analyses showed that XAD4 and FPX66 led to a reduction of the initial amount of volatile compounds to 14.05% and 15.72%, respectively. These two resins also did not affect the physicochemical characteristics of the clarified cashew apple juice.

Optimization of extrusion variables for the production of snacks from by-products of rice and soybean

This study aimed to define the process conditions to obtain snacks from the by-products of rice and soybean with physical characteristics suitable for marketing. Therefore, the effects of moisture and extrusion temperature on the expansion and color of the products obtained experimentally obtained were evaluated, and the proximate composition of the by-products and that of the snack with greater desirability were determined. Response surface methodology and rotational central composite design were used, and desirability test based on the regression models adjusted was applied. The most desirable snack, with the highest expansion index (3.39), specific volume (13.5 mL.g-1), and the chromaticity coordinate a* (2.79), was obtained under 12 g.100 g-1 moisture and 85ºC of temperature in the third zone of the extruder. The snack produced under these conditions attained content of protein and lipid content 41 and 64% higher than that of the traditional corn snack. It can be concluded that producing extruded snack made form a mixture of broken grains, rice bran, and soybean okara (81:9:10) is technologically feasible, enabling the development of a new product with good nutritional value that can improve the diet of children, the main consumers of this type of food.

Assessing environmental impacts using a comparative LCA of industrial and artisanal production processes: "Minas Cheese" case

This study uses the Life Cycle Assessment (LCA) methodology to evaluate and compare the environmental impacts caused by both the artisanal and the industrial manufacturing processes of "Minas cheese". This is a traditional cheese produced in the state of Minas Gerais (Brazil), and it is considered a "cultural patrimony" in the country. The high participation of artisanal producers in the market justifies this research, and this analysis can help the identification of opportunities to improve the environmental performance of several stages of the production system. The environmental impacts caused were also assessed and compared. The functional unit adopted was 1 kilogram (Kg) of cheese. The system boundaries considered were the production process, conservation of product (before sale), and transport to consumer market. The milk production process was considered similar in both cases, and therefore it was not included in the assessment. The data were collected through interviews with the producers, observation, and a literature review; they were ordered and processed using the SimaPro 7 LCA software. According to the impact categories analyzed, the artisanal production exerted lower environmental impacts. This can be justified mainly because the industrial process includes the pasteurization stage, which uses dry wood as an energy source and refrigeration.

Characterization of goat milk and potentially symbiotic non-fat yogurt

Combining prebiotics and probiotic microorganisms improve quality in the formulation of foods. In this paper, the characteristics of goat milk and symbiotic yogurt were studied. Raw goat milk was analyzed and the skimming process was optimized. For the formulation of a potentially non-fat symbiotic yogurt made with skimmed goat milk, inulin, gelatin, sugar, and Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei subsp. rhamnoshus. Chemical characteristics, acceptability, and viability of lactic acid bacteria and probiotic culture were assessed. The protein and fat content of the raw milk was 2.90 and 3.56 g/100 mL, respectively. The optimum skimming process was obtained at 9,800 rpm and 4 °C for 15 minutes. The product formulated had a protein and fat content of 4.04 to 0.04 g/100 mL, good sensory properties, and acceptability of 95%. The lactic bacteria count was 9 × 10(7) CFU mL- 1, and probiotic culture count was higher than 1 × 10(6) CFU mL- 1, which guarantees their effect and capacity to survive in the digestive tract and spread in the intestine. The yogurt was stable during the 21 days of storage. Therefore, this study shows that goat milk yogurt is an adequate delivery vehicle of the probiotic culture L. casei and inulin.

Use of starter cultures isolated from native microbiota of artisanal sausage in the production of Italian sausage

The most promising microorganisms for use as starter cultures are those isolated from the native microbiota of traditional fermented products. The aim of this study was to evaluate the use of lactic acid bacteria selected from the native microbiota of sausages produced by spontaneous fermentation as starter cultures for the production of sausage. Strains of Lactobacillus plantarum 503 and 341 have the potential for use as starter cultures in the manufacture of Italian sausage type. The population of lactic acid bacteria in sausages was >8 log CFU.g-1 during fermentation, which caused the pH to decrease to <4.5. This decrease in pH and the water activity of < 0.90 of sausages ensures the safety and preservation of this product. Sausages produced with these lactic cultures fulfill the requirements for microbiological quality and composition of Italian sausage type. Our results suggest the possibility of using these starter cultures for the production of sausages with peculiar characteristics that contribute to the identity of the product.

Influence of heat treatment on the sensory and physical characteristics and carbohydrate fractions of french-fried potatoes (Solanum tuberosum L.)

AbstractThe aim of this study was to analyze the impact that heat treatment with salts and freezing processes on the sensory, instrumental, and physico-chemical characteristics of fried potatoes of the Monalisa cultivar. The potatoes were blanched in distilled water (P); sodium chloride solution (B1); calcium chloride solution (B2), and a solution with both of these salts (B3). They were then pre-cooked and frozen for 24 hours and for 30 days. After frying, sensory characteristics were analyzed (color, texture, flavor, oiliness), along with overall preference and instrumental determinations of texture, color, and oil content. Further tests were conducted on the sample with the best results in the sensory analysis (B1), along with sample P as a control, to determine granule microstructure, carbohydrate fractions, glycemic index, and glycemic load. Blanching B3, despite reducing oil absorption and providing less oiliness, obtained lesser overall preference. Freezing for 30 days increased the lightness, except for when sodium chloride was used, which intensified the color yellow. The use of sodium chloride did not interfere with the type of starch granules, nor with the formation of resistant starch; however, longer freezing time reduced the glycemic index and concentrated the dietary fiber content. All samples exhibited low glycemic index and moderate glycemic loads.

Lactose hydrolysis potential and thermal stability of commercial β-galactosidase in UHT and skimmed milk

Abstract The commercial enzyme (E.C. = 3.2.1.23) from Kluyveromyces lactis (liquid) and Aspergillus oryzae(lyophilized) was investigated for its hydrolysis potential in lactose substrate, UHT milk, and skimmed milk at different concentrations (0.7; 1.0 and 1.5%), pH values (5.0; 6.0; 6.5 and 7.0), and temperature (30; 35; 40 and 55 ºC). High hydrolysis rates were observed for the enzyme from K. lactis at pH 7.0 and 40 ºC, and from A. oryzae at pH 5.0 and 55 ºC. The enzyme from K. lactis showed significantly higher hydrolysis rates when compared to A. oryzae. The effect of temperature and β-galactosidase concentration on the lactose hydrolysis in UHT milk was higher than in skimmed milk, for all temperatures tested. With respect to the thermal stability, a decrease in hydrolysis rate was observed at pH 6.0 at 35 ºC for K. lactisenzyme, and at pH 6.0 at 55 ºC for the enzyme from A. oryzae. This study investigate the hydrolysis of β-galactosidase in UHT and skimmed milk. The knowledge about the characteristics of the β-galactosidase fromK. lactis and A. oryzae enables to use it most efficiently to control the enzyme concentration, temperature, and pH in many industrial processes and product formulations.

Modeling and kinetic study of bio-ethanol production from soy protein concentrate by-product

Abstract The aim of this work was to evaluate a non-agitated process of bioethanol production from soybean molasses and the kinetic parameters of fermentation using a strain of Saccharomyces cerevisiae (ATCC® 2345). Kinetic experiment was conducted in medium with 30% (w v-1) of soluble solids without supplementation or pH adjustment. The maximum ethanol concentration was in 44 hours, the ethanol productivity was 0.946 g L-1 h-1, the yield over total initial sugars (Y1) was 47.87%, over consumed sugars (Y2) was 88.08% and specific cells production rate was 0.006 h-1. The mathematical polynomial was adjusted to the experimental data and provided very similar parameters of yield and productivity. Based in this study, for one ton of soybean molasses can be produced 103 kg of anhydrous bioethanol.