Application of multi-criteria decision-making for optimizing the formulation of functional cookies containing different types of resistant starches: A physicochemical, organoleptic, in-vitro and in-vivo study.

This research aimed to develop a healthy cookie formulation containing different types of resistant starch, through the application of TOPSIS approach, as a potent feature of MCDM methodologies. Physicochemical investigations reveled that a harder, denser and less sticky dough was produced by the addition of both types of RS. The baking of these doughs resulted in the production of crumblier cookies of less spread ratio, lower porous crumb and whiter surface/crumb. Moreover, in-vitro digestibility of the cookies demonstrated that the baking process can adversely reduce the resistance of RS4 to the enzymolysis reactions. This phenomenon was further corroborated by in-vivo studies where the RS4 enriched cookies were less capable in reducing the postprandial blood glucose. TOPSIS, through successful solving of the multiple criteria decision 9 (alternatives) × 15 (evaluated attributes) matrix suggested that the cookie containing 15% RS is the best alternative in all aspects, possessing acceptable physicochemical/organoleptic attributes, and in-vivo/in-vitro dietary fiber.

Sourdoughs fermented by autochthonous Lactobacillus strains improve the quality of gluten-free bread.

Sourdoughs based on fermentation by lactobacilli have the potential to produce gluten-free maize-based bread with acceptable technological and rheological characteristics, nutritional quality, and more prolonged shelf life. Of the 17 treatments compared (with or without sourdough, and involving single and multiple LAB species), treatments 12C (Lactobacillus brevis, L sanfranciscensis + L. plantarum), and 8C (L. brevis + L. paralimentarius) showed the lowest rate of complex modulus, while treatments 11C (L. sanfranciscensis + L. brevis + L. paralimentarius) and 2C (L. brevis) led to the greatest reduction in baking loss. The crumb moisture content of all of the formulations decreased with storage. Breads produced with treatment 2C (L. brevis) had the highest crumb moisture content when freshly baked, while loaves produced with treatment 3C (L. paralimentarius) had the highest crumb moisture content after four days of storage. A sensory evaluation indicated that sourdough-based maize breads were superior to both control and chemically acidified breads. The optimal treatments were to use sourdough seeded with treatment 2C (L. brevis), with treatment 4C (L. plantarum), with treatment 8C (L. brevis + L. paralimentarius), or with treatment 11C (L. sanfranciscensis + L. brevis + L. paralimentarius).

Effects of different roasting methods on formation of acrylamide in pistachio.

Drying and roasting are conventional processes in the nut industry. However, roasting as an important procedure in nuts manufacturing may cause some physicochemical changes in nuts. Acrylamide is one of these chemical compounds that is formed due to the roasting process. Acrylamide is known as a neurotoxicant, carcinogen, and reproductive toxicant. In this study, raw and salted pistachios were roasted under three conditions including hot-air, infrared (IR), and microwave methods. Then, 80 pistachio kernels were analyzed by ultra-high-performance liquid chromatography. The results showed that all samples contained different ranges of acrylamide between 57 ± 0.86 and 851 ± 2.8 µg/kg. Besides, raw pistachios and sun-dried pistachios also contained acrylamide, with the amount of 57 ± 0.86 and 93 ± 1.07 µg/kg, respectively. The highest acrylamide amount was found in raw pistachio (unsalted) roasted by IR method, while lower acrylamide amount observed in the microwave method. The amount of acrylamide in salted and roasted pistachios was less than just roasted pistachios under the same conditions. Finally, in all the treatments, increasing temperature, time, voltage, and power lead to an increase in acrylamide levels. The results showed that acrylamide in the roasted pistachios may cause health problems. This study presents a novel investigation in the effects of roasting conditions (temperature, power, voltage, and time) on acrylamide content in pistachios.

Lactobacillus-fermented sourdoughs improve the quality of gluten-free bread made from pearl millet flour.

The study investigated the effect of sourdough made from combinations of four Lactobacillus spp. on the physicochemical properties, consumer acceptability, and shelf life of bread made from pearl millet flour. Fermentation based on both single and multiple species reduced the pH of the dough and increased its titratable acidity and H2O2 content. The addition of sourdough increased the elasticity and reduced the stiffness of the pearl millet dough. Sourdough fermented with L. brevis had the greatest effect on loaf height, specific volume, porosity, and moisture content. During storage, the moisture content of the bread crumb decreased, but that of their crust increased. Sourdough-based loaves retained their moisture better than conventional loaves and the sourdough suppressed the development of mold for a longer period. An organoleptic assessment showed that the sourdough-based bread was more palatable than either conventional or chemically acidified ones. The tissue softness, chewiness, and flavor of the pearl millet bread decreased during storage. The use of sourdough based on either L. brevis, L. paralimentarius, or L. brevis + L. paralimentarius is recommended to produce high-quality pearl millet-based bread.

Physicochemical and morphological properties of resistant starch type 4 prepared under ultrasound and conventional conditions and their in-vitro and in-vivo digestibilities.

In the present work, cross-linked resistant starch (RS4) was prepared under sonication and conventional conditions at various levels of pH (9-12) and cross-linker concentration (sodium trimetaphosphate/sodium tripolyphosphate 99:1, 5-15%). It was found that phosphorous and resistant starch content was generally increased by increasing the cross-linker concentration, pH and application of sonication. The damage to the surface of sonicated granules was revealed by scanning electron micrographs. The presence of cross-linked phosphorous groups was demonstrated by FT-IR results through the appearance of a new peak at wave numbers of 1248-1252 cm-1 that was more conspicuous in sonicated cross-linked samples. Sonicated cross-linked starches showed higher gelatinization temperatures and lower degrees of crystallinity, while no changes was detected in terms of A-type crystalline pattern. The development of viscosity was diminished prominently by the extreme cross-linking reactions in both sonicated and conventional cross-linked starches. The least glycemic index value was obtained for sonicated cross-linked starches which was negatively correlated to their higher RS content measured in-vitro. These results provide novel information on the preparation of cross-linked resistant starch under sonication conditions.

Combined infrared-vacuum drying of pumpkin slices.

Infrared-vacuum dehydration characteristics of pumpkin (Cucurbita moschata) were evaluated in a combined dryer system. The effects of drying parameters, infrared radiation power (204-272 W), system pressure (5-15 kPa), slice thickness (5 and 7 mm) and time (0-220 min) on the drying kinetics and characteristics of pumpkin slices were investigated. The vacuum pressure, lamp power and slice had significant effect on the drying kinetics and various qualities of the dried pumpkin. Moisture ratios were fitted to 10 different mathematical equations using nonlinear regression analysis. The quadratic equation satisfactorily described the drying behavior of pumpkin slices with the highest r value and the lowest SE values. The effective moisture diffusivity increased with power and ranged between 0.71 and 2.86 × 10(-9) m(2)/s. With increasing in infrared radiation power from 204 to 272 W, ß-carotene content of dried pumpkins decreased from 30.04 to 24.55 mg/100 g. The rise in infrared power has a negative effect on the color changes (ΔE). The optimum condition was determined as power, 238W, pressure, 5 kPa and slice thickness, 5mm. These conditions resulted into dried pumpkin slices with maximum B-carotene retention.

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions.

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12%. The final optimum nano-emulsion formulation with 12% dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size<100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid.

Effect of resistant starch and aging conditions on the physicochemical properties of frozen soy yogurt.

The present study investigated the effects of resistant starch concentration (0, 1, 2 %), aging time (2, 13, 24 h) and aging temperature (2, 4, 6 °C) on the physicochemical properties of frozen soy yogurt. The results showed that resistant starch increased viscosity because of its water binding properties. Resistant starch also increased foam stability, fat destabilization, and hardness, but it decreased overrun and meltdown rate. Viscosity, hardness and fat destabilization increased as aging time increased. An increase in aging temperature decreased viscosity, overrun, hardness and fat destabilization of frozen yoghurt, but increased the meltdown rate.

Effect of thermal and freezing treatments on rheological, textural and color properties of basil seed gum.

Hydrocolloids are macromolecular carbohydrates that are added to many foodstuffs to achieve the appropriate rheological and textural properties and to prevent synersis or to increase the viscosity and stability of foodstuffs. In this study the effect of different thermal treatments (25, 50, 75, 100 and 121°C for 20 min) and freezing treatments (-18 and -25 °C for 24 h) on rheological, textural and color change of basil seed gum as a new source of hydrocolloids was investigated. The results demonstrated that basil seed gum solutions had desirable rheological and textural properties. Power law model well described non-newtonian pseudoplastic behavior of basil seed gum in all conditions. When the hydrocolloid samples were heated or frozen, increase in viscosity of basil seed gum solutions was observed. Hardness, adhesiveness and consistency of basil seed gel for control sample were 13.5 g, 16.79, 52.59 g.s, respectively and all increased after thermal treatments. The results revealed that basil seed gum has the excellent ability to stand against heat treatment and the highest hardness, adhesiveness and consistency value of gum gels were observed in sample treated at 121 °C for 20 min. In addition this gum gel has the good ability to stand against freeze-thaw treatment and its textural properties improved after freezing. Therefore, basil seed gum can be employed as a textural and rheological modifier in formulation of foods exposed to thermal and freezing temperatures.

A mixture design approach to optimizing low cholesterol mayonnaise formulation prepared with wheat germ protein isolate.

The aim of this study was to optimize the mixture proportion of low cholesterol mayonnaise containing wheat germ protein isolate (WGPI) and xanthan gum (XG), as emulsifying agents in mayonnaise preparation. The mayonnaise prepared with different combinations of WGPI, egg yolk (0-9 % of each component) and XG (0-0.5 %). The optimized mixture proportions of low cholesterol mayonnaise were determined by applying the optimal mixture design method to acquire the mayonnaise with proper stability, texture, rheological properties and sensory scores. Optimum values of WGPI, XG and egg yolk in the mixture were found to be 7.87 %, 0.2 % and 0.93 %, respectively (of 9 % egg yolk). The WGPI, due to unique functional properties, had the greatest effect on properties of mayonnaise samples. Moreover, combination of XG and WGPI, improved the stability, heat stability, viscosity, consistency coefficient and textural properties of product. However, the overall acceptance was maximum in a mixture contained high amount of WGPI and XG and low amount of egg yolk. The results of this research showed the feasibility of preparation a low cholesterol mayonnaise by application a desirable combination of WGPI, XG, and egg yolk, with comparable properties those of the conventional mayonnaise.

Effect of inulin on the physicochemical properties, flow behavior and probiotic survival of frozen yogurt.

This study investigated the effect of inulin (0, 1 and 2 %), on some physicochemical properties of frozen yogurt, as well as its effect on flow behavior and probiotic survival. The results showed that the addition of inulin improved overrun, viscosity and melting properties significantly (p < 0.05); when added at 2 % level, it also had significant effect on pH. Total acceptability of samples revealed that frozen yogurt with 2 % inulin had the most appealing sensory characteristics. The flow behavior of all samples showed their pseudoplastic nature; power law was the best model to predict their flow behavior. In terms of probiotic survival, the sample with 2 % inulin significantly improved the viability of Lactobacillus acidophilus and Bifidobacterium lactis.

Enhanced biomass delignification and enzymatic saccharification of canola straw by steam-explosion pretreatment.

BACKGROUND: In recent decades, bioconversion of lignocellulosic biomass to biofuel (ethanol and biodiesel) has been extensively investigated. The three main chemical constituents of biomass are cellulose, hemicellulose and lignin. Cellulose and hemicellulose are polysaccharides of primarily fermentable sugars, glucose and xylose respectively. Hemicellulose also includes small fermentable fractions of arabinose, galactose and mannose. The main issue in converting lignocellulosic biomass to fuel ethanol is the accessibility of the polysaccharides for enzymatic breakdown into monosaccharides. This study focused on the use of steam explosion as the pretreatment method for canola straw as lignocellulosic biomass. RESULTS: Result showed that steam explosion treatment of biomass increased cellulose accessibility and it hydrolysis by enzyme hydrolysis. Following 72 h of enzyme hydrolysis, a maximum cellulose conversion to glucose yield of 29.40% was obtained for the steam-exploded sample while the control showed 11.60% glucose yields. Steam explosion pretreatment increased glucose production and glucose yield by 200% and 153.22%, respectively, compared to the control sample. The crystalline index increased from 57.48% in untreated canola straw to 64.72% in steam-exploded samples. CONCLUSION: Steam explosion pretreatment of biomass increased cellulose accessibility, and enzymatic hydrolysis increased glucose production and glucose yield of canola straw.

Soluble soybean polysaccharide: a new carbohydrate to make a biodegradable film for sustainable green packaging.

Biodegradable edible films based on soluble soybean polysaccharide (SSPS), a new film-forming material, and three levels of glycerol (20%, 30% and 40%, w/w) as plasticizer, were developed and evaluated in terms of physical, mechanical, barrier and optical properties as well as their microstructure. SSPS-based films with a concentration of 20% glycerol possessed the lowest water vapor permeability. Increasing the glycerol content increased (P<0.05) values for elongation at break, but decreased (P<0.05) tensile-strength values. It was found that plasticizer concentration significantly affected the films' glass-transition temperature; however, it had no significant effect on their melting point. Color measurement showed that increasing the glycerol concentration caused the b and L values to increase, while ΔE value decreased. These results were explained by the film's microstructure, which was analyzed by atomic force microscopy and scanning electron microscopy. The results indicated that SSPS could be a promising food-packaging material.