Physicochemical and functional characteristics of a gourd (Cucurbita argyrosperma Huber) seed protein isolate subjected to high-intensity ultrasound.

The impact of high-intensity ultrasound (HIU, 20 kHz) on the physicochemical and functional characteristics of gourd seed protein isolate (GoSPI) was studied. GoSPI was prepared from oil-free gourd seed flour through alkaline extraction (pH 11) and subsequent isoelectric precipitation (pH 4). The crude protein concentration of GoSPI ranged from 91.56 ± 0.17 % to 95.43 ± 0.18 %. Aqueous suspensions of GoSPI (1:3.5 w/v) were ultrasonicated at powers of 200, 400, and 600 W for 15 and 30 min. Glutelins (76.18 ± 0.15 %) were the major protein fraction in GoSPI. HIU decreased the moisture, ash, ether extract, and nitrogen-free extract contents and the hue angle, available water and a* and b* color parameters of the GoSPI in some treatments. The L* color parameter increased (7.70 %) after ultrasonication. HIU reduced the bulk density (52.63 %) and particle diameter (39.45 %), as confirmed by scanning electron microscopy, indicating that ultrasonication dissociated macromolecular aggregates in GoSPI. These structural changes enhanced the oil retention capacity and foam stability by up to 62.60 and 6.84 %, respectively, while the increases in the solvability, water retention capacity, and emulsifying activity index of GoSPI were 90.10, 19.80, and 43.34 %, respectively. The gelation, foaming capacity, and stability index of the emulsion showed no improvement due to HIU. HIU altered the secondary structure of GoSPI by decreasing the content of α-helices (49.66 %) and increasing the content of ß-sheets (52.00 %) and ß-turns (65.00 %). The electrophoretic profile of the GoSPI was not changed by HIU. The ultrasonicated GoSPI had greater functional attributes than those of the control GoSPI and could therefore be used as a functional food component.

Effect of high-intensity ultrasound on the compositional, physicochemical, biochemical, functional and structural properties of canola (Brassica napus L.) protein isolate.

The objective of this study was to investigate the impacts of high-intensity ultrasound treatments on the compositional, physicochemical, biochemical, functional and structural properties of canola protein isolates (CPI). Aqueous canola protein suspensions were sonicated at 40 kHz for 15 min and 30 min. The moisture content, water activity, bulk density and the L* and a* color parameters of the CPI decreased due to the ultrasound; however, the in vitro protein digestibility was not modified by the treatment. Glutelin (57.18%) was the main protein fraction in the canola protein isolate. SDS-PAGE demonstrated that there were no changes in the protein electrophoretic patterns, thus indicating that sonication did not break the covalent bonds. However, the ultrasound treatment improved the protein solubility, oil absorption capacity and the emulsifying, gelation and foaming properties, but these improvements depended on the pH and ultrasound exposure time. Scanning electron microscopy revealed that the ultrasound treatment disrupted the microstructure of the CPI by exhibiting larger aggregates as a lyophilized powder. In addition, there was an increase in the surface hydrophobicity and a decrease in the size of the particles of the canola protein due to the ultrasound effects, which indicates a destruction of the particles or a dissociation of the protein aggregates in the canola protein dispersions. These results suggest that ultrasound treatment is a valuable tool for improving the characteristics of canola proteins for use in foods.

Effect of soaking in noni (Morinda citrifolia) juice on the microbiological and color behavior of Haden minimally processed mango.

The purpose of this study was to evaluate the effect of soaking in noni juice on the microbiological and color behavior of minimally processed mango. Two batches of Haden mango cubes were treated by immersion in noni juice for 2.5 or 5.0 min. Each batch was packed in polypropylene boxes and stored at 6 °C for up to 15 days; in addition, a control group of mango cubes was prepared by immersion in sterile water for the same duration. According to the results, the soaking of mango cubes in noni juice had an antimicrobial effect on mesophilic aerobic bacteria, molds and yeasts during storage at 6 °C for 15 days, without significantly (P < 0.05) affecting the CIE L*, a*, b*, chroma and hue angle values, in comparison with the control after 12 days of storage. The noni juice soaking treatment was demonstrated to be a potentially valuable technology for decontamination of fresh-cut fruit surfaces.

Chemical, Physicochemical, Nutritional, Microbiological, Sensory and Rehydration Characteristics of Instant Whole Beans (Phaseolus vulgaris).

Instant whole beans obtained by drying at 25 °C were evaluated for their chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics. The proximal composition of instant whole beans was typical of this kind of food, whereas aw and L*, a* and b* values were 0.639, 98.55, -0.28 and -1.52, respectively. In instant whole beans, 75% of the essential amino acids had a value greater or equal to the reference standard for adult humans; the protein quality in terms of chemical score was 95%. Microbiological counts of aerobic mesophilic bacteria, moulds, yeasts and total coliforms of rehydrated instant whole beans were <10 CFU/g, whereas the scores for colour, flavour, texture and overall acceptability were 7.22, 7.68, 7.24 and 7.34, respectively, on a 1-9 hedonic scale. The logarithmic and Pilosof models showed close fits (R2>0.99) to the experimental data for drying of cooked beans and rehydration of instant whole beans, respectively. In the light of the chemical, physicochemical, nutritional, microbiological, sensory and rehydration characteristics of instant whole beans found in this study, drying at 25 °C is recommended for the production of such food.

Preparation of biological fish silage and its effect on the performance and meat quality characteristics of quails (Coturnix coturnix japonica)

The aim of the present study was to produce fish silage by lactic acid fermentation and evaluate its use in feeding of quails (Coturnix coturnix japonica). An oven-dried mixture of fish silage and soybean meal (1:1 w/w) was used to prepare the diets with different levels of inclusion (0, 10, 20 and 30%) and evaluate its effect on the performance and meat quality of 160 quails. The inclusion level did not affect the growth and feed conversion ratio. The carcass yield (70.3%) and sensory quality of breast meat were not significantly different among the treatments (p>0.05). However, the concentration of unsaturated fatty acids such as oleic (C18:1n9C), linoleic (C18:2n6C), linolenic (C18:3n3), arachidonic (C20:4n6), cis eicosapentaenoic (C20:5n3) and cis docosahexaenoic (C22:6n3) increased in quail breast meat with the inclusion of fish silage:soybean mixture in the diet (p<0.05). Fish silage and its use in quail diets could offer a good alternative for fish waste utilization as feedstuff component for the improvement of fatty acid composition in its breast meat.

Desarrollo de una fórmula médica a partir de un concentrado proteínico de garbanzo (Cicer arietinum) / Development of a feeding formula from a protein concentrate of chick-pea (Cicer arietinum)

A medical formula was developed from a chick-pea (Cicer arietinum) protein concentrate obtained by ultrafiltration (67.8 per cent of protein). Additionally sucrose, methionine, milk flavor, and mixtures of corn and coconut oils, vitamins and minerals were used, to perform FAO/WHO standards. All ingredients were blended in water to 50 degrees C, and the mixture was spray-dried with a Spray-drier using inlet and outlet air temperatures of 170 and 90 degrees C respectively. The nutritive value of the formula was evaluated with the Net Protein Ratio (NPR), Nitrogen Utilization (NU) and both relatives values to casein ANRC (R-NPR and R-NU). The proximal analysis of the infant formula was: protein 16.0 per cent (with 4.9 g/16 g N of reactive lysine), fat 25.8 per cent , moisture 4.0 per cent , ash 3.2 per cent and carbohydrates 51.0 per cent . The values of NPR, R-NPR, NU and R-NU were 3.95, 83.6, 3.55 and 82.5 respectively. This results shown the chick-pea protein concentrate, potencially utilizable as an ingredient in the formulas for medical purposes

Obtención de un concentrado proteínico de garbanzo (Cicer arietinum) por ultrafiltración / Obtention of protein concentrate chickpea (Cicer arietinum) by ultrafiltration

Se obtuvo un concentrado proteínico de garbanzo (Cicer arietinum) a partir de sus extractos acuosos. Los parámetros de extracción de proteínas objeto de estudio fueron la relación harina: agua y el pH. Los solidos de los extractos acuosos se concentraron en una umidad de ultrafiltración tamaño piloto Romicon HF1/2SSS, equipada con cartucho de fibra hueca, con membranas de peso molecular nominal de 50,000 daltones. Los sólidos concentrados por ultrafiltración se secaron por asperción, y el producto obtenido presentó la siguiente composición expresada en g/100 g: proteína, 67.8 con 4.9 g/16 g N de lisina reactiva; lípidos, 17.3; carbohidratos, 10.0; y cenizas, 4.9 (en base seca). El índice de solubilidad de nitrógeno fue de 93 y el color por Hunter de L=86.8