Yoon Kil Chang

Antioxidant and antiinflammatory properties of germinated and hydrolysed Brazilian soybean flours

The effect of germination in combination with Alcalase hydrolysis of Brazilian soybean cultivar BRS 133 on the production of soybean flours with bioactive peptides as modulators of oxidative stress and markers of inflammation was monitored. The electrophoretic profile showed a weak protein breakdown during germination. However, a strong breakdown of the proteins can be observed after the first hour of hydrolysis with Alcalase. MALDI-TOF-MS analysis of the protein extracts showed differences in the intensity and profile of peptide mass fingerprint due to germination and hydrolysis. Germinated flour showed higher soluble protein concentration and antioxidant capacity. All soybean protein extracts and protein hydrolysates produced (G0, G18 and G72) showed a significant (p<0.05) inhibition on inflammatory markers such as nitric oxide (20.5-69.3%), iNOS (22.8-93.6%), PGE(2) (64.0-88.3%), COX-2 (36.2-76.7%), and TNF-α (93.9-99.5%) in LPS-induced RAW 264.7 macrophages. However, protein extracts of flours with 18 h of germination were more potent in inhibiting pro-inflammatory responses when compared to 72 h. It can be concluded that a combination of 72 h of soybean BRS 133 germination and 1h Alcalase hydrolysis resulted in the formation of bioactive compounds with more potent antioxidant activity, and improvement in the reduction of some of the markers of inflammation.

Physicochemical and rheological characteristics of commercial nixtamalised Mexican maize flours for tortillas

Three commercial nixtamalised Mexican maize flours (CNMFs) designated HI-A, HI-B and HI-C were evaluated in this work. For each brand, four samples corresponding to four consecutive months of production were evaluated. Tortillas prepared by the traditional process of nixtamalisation were used as the control. The maize flours and their respective tortillas showed variations between samples in their physical, chemical and rheological parameters. The three commercial maize flours incorporated additives and preservatives. The moisture content, colour, pH, subjective water absorption capacity, water solubility index, water absorption index and swelling capacity of flours showed strong differences between the three CNMFs with respect to the chemical analysis. Important differences in the protein, calcium and amylose contents were observed. Tortillas from CNMFs had a blander maize flavour, less desirable texture and staled more rapidly than traditional tortillas. Some modifications are required in the current Official Mexican Quality Standard, principally in the appropriate selection of additives and levels used in the preparation of CNMFs.

Effects of Calcium Hydroxide and Processing Conditions on Corn Meal Extrudates

ABSTRACT The effects of added calcium hydroxide (0.0, 0.15, 0.25, and 0.35%) and processing conditions, feed moisture content (mc) (16, 18, and 20%) and barrel temperature (130 and 150°C) on characteristics of corn meal extrudates were studied. Extruder screw speed was maintained at 130 rpm. Corn meal was extruded with a single-screw extruder (Brabender model GNF 1014/2) with a screw compression ratio of 3:1. The highest values (P < 0.05) for radial expansion and the lowest values for density and breaking force of extrudates were found for the treatment with 0.00% calcium hydroxide extruded at 16% feed mc and 130°C barrel temperature. This treatment was statistically different from the other treatments. Best values for radial expansion of samples extruded with added calcium hydroxide were for the samples with 0.15% calcium hydroxide at 18% feed mc and 130°C barrel temperature, followed by the sample with 0.35% calcium hydroxide at 16% feed mc and 130°C barrel temperature. Water absorption index and water ...

Effect of Infrared Baking on Wheat Flour Tortilla Characteristics

ABSTRACT A new and improved method for baking wheat flour tortillas was evaluated. The method was faster and reduced tortilla dehydration. The aim of the study was to evaluate the efficiency of the infrared baking method on rollability, puffing, layering, color (lightness), and texture (cutting force and tensile strength) characteristics of wheat tortillas formulated and formed by the traditional (hand-rolled) and commercial (hot-press) methods. These tortillas were also compared with traditional tortillas cooked on a hot griddle and commercial tortillas cooked in a three-tier, gas-fired oven. In the infrared radiation (IR) method, tortillas were baked for 17 or 19 sec by IR using black-body radiation at a selected wavelength band and emission temperatures of 549 or 584°C. IR-baked tortillas showed good characteristics of rollability, puffing, layering, color, and texture. The loss of moisture during baking of the tortillas formed by hot-pressing and baked by IR was significantly lower than that of tortil...

Use of jatoba (Hymenaea stigonocarpa Mart.) flour in the production of cookies and acceptance evaluation using univariate and multivariate sensory tests

The objective of this research was to investigate the use of jatoba (Hymenaea stigonocarpa Mart.) flour in the production of cookies. The jatoba flour was first characterized chemically. The cookies were prepared using a 9:1 proportion of wheat:jatoba flours and the addition of different types of sugar: brown sugar, brown sugar+honey, honey, fructose and finally refined sugar for the control formulation. The cookies were evaluated for their physical and sensory characteristics. The acceptance levels of the products and of some similar commercial products were evaluated by potencial consumers of the product in the distinct geographical regions: Campinas (State of Sao Paulo) and Goiânia (State of Goias). The jatoba flour had a moisture content between 8.44 and 10.9 g/100g and the following composition on a dry basis: 6.2±0.1 g protein/100 g, 4.04±0.08 g lipids/100g, 3.38±0.03 g ash/100g, 12.6±0.4 g soluble food fibre /100g, 36.4±0.3 g insoluble food fibre/100g, 3.1±0.1 g/100g starch and 34.28 g sugars/100g. The most acceptance product of those tested was the cookie prepared with the mixed jatoba and wheat flour plus brown sugar.

Impact of germination and enzymatic hydrolysis of cowpea bean (Vigna unguiculata) on the generation of peptides capable of inhibiting dipeptidyl peptidase IV

The objective of this work was to determine the impact of germination of cowpea (Vigna unguiculata), combined with enzymatic hydrolysis on the generation of bioactive peptides with dipeptidyl peptidase IV (DPP-IV) inhibition activity and antioxidant capacity. Germination (25°C, up to 48h) and alcalase hydrolysis (up to 4h) significantly increased antioxidant capacity of cowpea proteins from 293.4 to 993.7μmol TE/g soluble protein (SP). The non-germinated and 1h alcalase hydrolysates showed the highest DPP-IV inhibition (IC50=0.58mgSP/mL), after in vitro simulated gastrointestinal digestion. Selected peptides in the hydrolysates were analyzed by computational modeling. The TTAGLLE peptide interacted with S2 (GLU205, GLU206) and S3 (SER209, ARG358, PHE357) pockets of DPP-IV, and it is expected to inhibit DPP-IV by blocking its active site. Cowpea short time germination (24h) and alcalase protein hydrolysis (1h) can be used to produce ingredients with high antioxidant capacity and DPP-IV inhibition.

Effects of production by microwave heating after conventional baking on moisture gradient and product quality of biscuits (cookies)

ABSTRACT After conventional (forced-convection heating) baking at 240°C for 4 min, biscuits (cookies) were baked further in a microwave oven at medium and high settings (617.3 and 745.5 W, respectively) to study the effects of microwave baking on the moisture gradient and overall quality of the cookies. Microwave baking significantly (P 1.5%/cm produced significant levels of cracking. Cookies postbaked at a medium microwave power setting for 29 sec produced the sa...

Physical and Sensory Properties of Regular and Reduced-Fat Pound Cakes with Added Amaranth Flour

ABSTRACT The sum of wheat flour and corn starch was replaced by 10, 20, or 30% whole amaranth flour in both conventional (C) and reduced fat (RF) pound cakes, and the effects on physical and sensory properties of the cakes were investigated. RF presented 33% fat reduction. The increasing amaranth levels darkened crust and crumb of cakes, which decreased color acceptability. Fresh amaranth-containing cakes had similar texture characteristics to the controls, evaluated both instrumentally and sensorially. Sensory evaluation revealed that replacement by 30% amaranth flour decreased C cakes overall acceptability scores, due to its lower specific volume and darker color. Amaranth flour levels had no significant effect on overall acceptability of RF cakes. Hence, the sum of wheat flour and corn starch could be successfully replaced by up to 20% amaranth flour in C and up to 30% in RF pound cakes without negatively affecting sensory quality in fresh cakes. Moisture losses for all the cakes were similar, ≈1% per ...

Effect of Adding Different Dietary Fiber Sources on Farinographic Parameters of Wheat Flour

ABSTRACT Breadmaking is a complex process that involves a series of parameters that must be controlled. Rheological measurements are often used to predict the behavior of wheat dough during processing and the quality of the final product. There are many different dietary fiber sources that can be used to enhance the nutritional quality of bread. However, they will affect processing and final product quality. Response surface methodology (RSM) was employed to study the effects of adding different dietary fiber sources (wheat bran, resistant starch, and locust bean gum) on farinographic parameters of wheat flour. The experiments were conducted according to a 23 central composite rotational design (CCRD). With the experimental results or responses (farinographic parameters), the effect of each variable was calculated and the interactions between them were determined. Models that explain the effects of the different fiber sources on water absorption, arrival time, dough development time, and mixing tolerance ...

Thermoplastic Extrusion in Food Processing

Extrusion cooking was first introduced in food and feed processing in the late 1950s. Since then, the systems involved have grown in popularity, efficiency and flexibility. Extrusion cooking technology is most used for cereal and protein processing in the food industry and is closely related to the pet food and feed sectors. In the last decade, the development of extruders has evolved to yield sophisticated products, new flavour generation, encapsulation and sterilisation.