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Mushrooms are health foods due to their nutritional values and antioxidant properties. This study investigated chemical properties, total phenolic content (TPC), antioxidant activities (2, 2-diphenyl-1-picrylhydrazyl; DPPH and 2, 2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid); ABTS) and selected phenolic acids from five different tray-dried and freeze-dried mushrooms (Pleurotus ostreatus, Pleurotus pulmonarius, Schizophyllum commune, Volvariella volvacea and Lentinus edodes). The extracts were prepared using methanol and hot water extractions. The results revealed that V. volvacea had the highest protein (28.70%) and ash (9.48%) contents. There were significant differences among some tray dried and freeze dried mushrooms regarding TPC, DPPH and ABTS. However, tray drying tended to improve TPC, DPPH and ABTS in P. ostreatus, P. pulmonarius and L. edodes. Among five mushroom species, both methanol and hot water extractions of V. volvacea had the highest TPC, DPPH and ABTS values but there were no significant differences between mushrooms prepared using tray drying and freeze drying. Moreover, the yield and contents of gallic acid and p-hydroxybenzoic acid from the hot water extracts were higher than from the methanol extracts. Therefore, tray-dried V. volvacea had the most potential as a natural antioxidant and could be used as a functional ingredient in healthy food products.

The effects of three levels of pumpkin flour (PF; 10, 20 and 30%) and three levels of feed moisture content (FM; 13, 16 and 19%) on the physical properties, antioxidant activity and sensory properties of pumpkin-germinated brown rice extrudates were investigated. The increase in the PF increased the bulk density, hardness, total phenolic content (TPC) and antioxidant activity, but decreased the expansion ratio of the extruded snack. Decreasing the FM caused an increase in the TPC and antioxidant activity of the snack product. The predicted optimum formulation of extrudates using response surface methodology was 10–13% PF and 13–14% FM under extrusion conditions at 140 °C (zone 6) and 350 rpm screw speed. These conditions produced extruded snacks with TPC values of 20–28 mg GAE/100 g sample on a dry basis and appearance and hardness liking scores of more than 6.5 (on a 9-point hedonic scale). Therefore, the results of this study supported the utilization of PF and germinated brown rice flour to develop healthy snack products. Keywords: Antioxidant activity, Extrusion, Germinated brown rice flour, Pumpkin flour, Snack

Dried squid head is an abundant–low value by product from dried squid snack industry. The head is consisted of high protein content with the abundant sweet-umami amino acid, glutamic acid (7.45 mg/100 mg). The major volatile compounds found are trimethylamine and toluene along with the 15 important compounds exhibited dried squid flavor. Enzymatic hydrolysis with Flavourzyme® was performed at the optimal pH and temperature in order to produce flavored-functional protein hydrolysate. The supernatant was collected at 0, 30, 60, 90, 120, 150, 180 and 210 min of hydrolysis. The sweet-umami hydrolysate solution with the highest liking score at 6.64 was obtained after 180 min of hydrolysis. This sample was subjected to dry using freeze drying and foam-mat drying and investigated the changes of flavor compounds and functional properties. The freeze dried sample had umami taste and light brown color, and possessed the various types of volatile compounds. It contained protein at 76.42%, and EAI at 22.00, while the foam-mat dried sample had the highest ESI (15.27) and FS (29.87). The antioxidant property of the freeze dried sample (ABTS scavenging activity at 14.77 mg/g, FRAP scavenging activity at 5.93 mmol Fe2SO4 7H2O/g and DPPH scavenging activity at 19.51%, respectively) was higher than that of the foam-mat dried sample. Hence, it could be used as flavored-functional ingredient in foods.

Summary Physicochemical properties (pasting and thermal properties, swelling power, water solubility and antioxidant activities) and chemical composition of pumpkin flour (PF) and starches, isolated from fresh pumpkin (SFF) or flour (SFP) were compared. SFP and SFF had similar proximate composition and amylose content. Drying process during PF preparation modified starch properties. PF exhibited greater antioxidant activities (DPPH, ABTS and FRAP), but had lower β-carotene than fresh pumpkin. SFF and SFP had higher amylose content than PF, and exhibited a B-type X-ray diffraction pattern with spherical and dome-like starch granules. Peak viscosity of SFP was relatively higher than that of SFF, probably due to lower swelling power and water solubility, which indicated increased granular rigidity in the SFP starch structure. Compared with SFF and SFP, PF had significantly higher onset (To), peak (Tp) and conclusion (Tc) temperatures due to a lower starch content and relatively higher fibre content, which resulted in lower gelatinisation enthalpy (ΔH).

The effects of the enzyme type (Alcalase, Flavourzyme and Neutrase) and hydrolysis time (2, 4 and 6 h) on properties of rice bran protein hydrolysate (RBPH) were studied. The enzyme type had significant effects on the protein yield and the properties of RBPH whereas the hydrolysis time was less influence. There were small differences in the total phenolic content and the ABTS radical scavenging activity between protease-hydrolyzed and unhydrolyzed rice bran protein, but enzymatic hydrolysis using Alcalase was the most effective providing hydrolysate with the highest protein yield and protein content. The optimal hydrolysis conditions was 2 h using an Alcalase-yielding protein content of 30.3%, a protein yield of 56.6%, TPC of 22.1 mg GAE/g, ABTS of 7.57 mg GAE/g and FRAP of 152 mM Fe 2+ /g. Fractionated peptides from this hydrolysate using anion exchange chromatography showed high antioxidant activity containing both positive and negative charge fractions with a low M W of 6 kDa. The RBPH using Alcalase could be a protein source and antioxidant in functional foods and beverages.

Summary Protein hydrolysate from pigmented Riceberry rice bran has great potential to be used in food products due to its protein content and antioxidative activities. In this study, characteristics, solubility, heat stability and emulsification properties of protein hydrolysates from the bran fraction of two rice cultivars, commercial rice bran (CBH) and Riceberry bran (RBH), were investigated. Both CBH and RBH showed the lowest solubility near their isoelectric point between pH 2 and 3. Solubility of RBH increased with increasing pH as the hydrolysates became more negatively charged; however, solubility of CBH was less dependent on pH. Heating did not significantly affect solubility of both hydrolysates which could be due to reduced aggregation of low-molecular weight peptides and/or the exposure of charged and polar groups after hydrolysis. Oil-in-water emulsions stabilised by RBH were more stable compared to those stabilised by CBH. Maximum stability was achieved with RBH at pH 6 where no creaming was observed after 14 day storage. Higher stability could be due to increased surface protein coverage, more negative charge and higher viscosity of RBH-stabilised emulsions. In addition, higher carbohydrate content and the presence of flavonoid could also contribute to an increase in stability. These results can be applied in food products using rice bran protein hydrolysate as nutritional ingredients.

Rice bran oil (RBO) is used in several products in the food, cosmetics, and pharmaceutical industries due to its desirable health, flavor, and functional attributes. The formation and physicochemical properties of microencapsulated RBO stabilized by different biopolymers were investigated. Oil-in-water emulsions (10% RBO, citrate buffer pH 7) stabilized by either 3.5% whey protein isolate (WPI) or 7.0% modified starch (MS) containing maltodextrin (DE18) as a carrier agent were initially prepared. The diameter of emulsion droplets produced by WPI and MS were considerably smaller than 300 nm and 25 μm for dried particles. The resulting powders had poor to fair flowability and high cohesiveness characteristics: Carr index (27–37) and Hausner ratio (1.4–1.6). The microencapsulation efficiency of the spray-dried powders ranged from 92–95%. Moisture sorption isotherms of the powders were determined by a gravimetric method, while their glass transition temperatures (Tg) were determined by differential scanning c...

Summary Effects of extrusion and drum-drying treatments on physico-functional and antioxidant properties of flours prepared from purple-flesh sweet potato were evaluated. Extrusion variables were feed moisture contents (MC; 10%, 13%, 16%) and screw speeds (SS; 250, 325, 400 r.p.m.), whereas drum-drying was done at 120, 130 or 140 °C. Effects of MC were generally greater than SS on flour properties. Extruded flours showed higher water absorption and water solubility indices compared with control nonextruded flours. Regardless of SS, total phenolic content and antioxidant activities (DPPH and ABTS) of flours processed at 10% MC were significantly higher than those at 13% and 16%. Both extruded and drum-dried flours exhibited no peak viscosity, indicating complete gelatinisation of starch. Maximum phenolic content and antioxidant activities of drum-dried flours were obtained at 140 °C. Although drum-dried flours had higher antioxidant capacity than extruded flours, both flours could potentially be used as food ingredients.

UNLABELLED Four (coconut, palm, rice bran, and soybean) edible oils and glycerol were applied on eggshell. All noncoated and coated eggs were stored for 5 wk at 25 ± 2 °C and drawn weekly for quality evaluation. All oil coatings were more effective in preserving internal quality of eggs than was glycerol coating. As storage time increased, the preservative effects of edible oil coating on weight loss, and albumen and yolk quality were significantly noticed. Oil-coated eggs had significantly lower weight loss (

The objective of this research was to evaluate the influence of storage pH (3 and 7) and biopolymer emulsifier type (Whey protein isolate (WPI), Modified starch (MS) and Gum arabic (GA)) on the physical and oxidative stability of rice bran oil-in-water emulsions. All three emulsifiers formed small emulsion droplets (d32 < 0.5 lm) when used at sufficiently high levels: 0.45%, 1% and 10% for WPI, MS and GA, respectively. The droplets were relatively stable to droplet growth throughout storage (d32 < 0.6 lm after 20 days), although there was some evidence of droplet aggregation particularly in the MS-stabilized emulsions. The electrical charge on the biopolymer-coated lipid droplets depended on pH and biopolymer type: 13 and 27 mV at pH 3 and 7 for GA; 2 and 3 mV at pH 3 and 7 for MS; +37 and 38 mV at pH 3 and 7 for WPI. The oxidative stability of the emulsions was monitored by measuring peroxide (primary products) and hexanal (secondary products) formation during storage at 37 C, for up to 20 days, in the presence of a pro-oxidant (iron/EDTA). Rice bran oil emulsions containing MS- and WPIcoated lipid droplets were relatively stable to lipid oxidation, but those containing GA-coated droplets were highly unstable to oxidation at both pH 3 and 7. The results are interpreted in terms of the impact of the electrical characteristics of the biopolymers on the ability of cationic iron ions to interact with emulsified lipids. These results have important implications for utilizing rice bran oil, and other oxidatively unstable oils, in commercial food and beverage products.

Summary This study revealed that the storage duration (2, 4, 6, 8, 10 and 12 months) of paddy rice and pH (3 and 6.8) of steeping water during germination were significantly influenced the physicochemical properties of germinated brown rice flour (GBRF). GBRF obtained at pH 3 vs. 6.8 provided the highest both reducing sugar content and free gamma-aminobutyric acid (GABA) content (99.8 vs. 54.2 mg per 100 g flour respectively) as the paddy rice was stored for 8 months. The peak viscosity of GBRF obtained at pH 3 and 6.8 exhibited the lower values than that of non-GBRF throughout the storage. From the principal component analysis, reducing sugar had a positive correlation with α-amylase activity whereas a negative correlation was found with peak viscosity. GBRF from paddy rice stored for 8 months and germinated at pH 3 possessed the highest free GABA content, 50 times of the non-GBRF, which can be further utilised in functional and healthy foods.

Summary Selected physicochemical properties of composite [wheat/germinated brown rice (GBRF)/germinated glutinous brown rice (GGNBRF)] flours at 100:0:0 (control), 70:30:0, 60:30:10, 60:40:0 and 50:40:10 (%) were evaluated. Germination (steeping at pH 3 for 24 h at 35 °C) increased free gamma-aminobutyric acid from 2.11 to 32.7 and 2.41 to 30.69 mg per 100 g flour for GBRF and GGNBRF, respectively. The 60:30:10 and 50:40:10 composite flours exhibited the lower peak viscosity (70.42 and 68.54 RVU, respectively). The setback viscosity of composite flours containing GGNBR was significantly lower than other flours. The presence of GBRF and GGNBRF significantly lowered specific volume and expansion ratio of breads. However, all sensory liking scores, except for appearance, were not significantly different among composite flour breads. Overall liking scores of all breads ranged from 6.8 to 7.2 (like moderately). This study demonstrated feasibility of incorporating GBRF and GGNBRF up to 50% by weight in bread formulations without compromising sensory liking.

Summary Effects of glucose syrup (2%, 4%, and 6%) and pectin (0.5%, 1.0%, and 1.5%) concentrations on physicochemical characteristics and sensory acceptability of machine-formed pineapple leather snack were investigated. Changes in glucose syrup and pectin concentrations significantly affected velocity of forming and total soluble solids content of pineapple paste, but did not affect thickness of pineapple leathers. Increasing pectin concentrations generally increased redness (a*) and yellowness (b*), and hardness (tensile force and work) while decreased moisture content and aw of pineapple leathers. Two most acceptable pineapple leathers were prepared with 6% glucose syrup and 0.5–1.0% pectin. Increasing pectin concentration from 1.0% to 1.5% negatively affected toughness acceptability, which was attributed to reduced moisture and aw, and increased tensile force and work. The optimum formulation range consisted of 3.5–6.0% glucose syrup and 0.5–1.0% pectin, yielding products with acceptability scores of 6.7–7.3 (on a 9-point hedonic scale) for appearance, sourness, sweetness, overall-taste, toughness and overall-liking.

Rice bran oil (RBO) is used in foods, cosmetics, and pharmaceuticals due to its desirable health, flavor, and functional attributes. We investigated the effects of biopolymer emulsifier type and environmental stresses on the stability of RBO emulsions. Oil-in-water emulsions (5% RBO, 10 mM citrate buffer) stabilized by whey protein isolate (WPI), gum arabic (GA), or modified starch (MS) were prepared using high-pressure homogenization. The new MS used had a higher number of octenyl succinic anhydride (OSA) groups per starch molecule than conventional MS. The droplet diameters produced by WPI and MS were considerably smaller (d300 nm) than those produced by GA (d1000 nm). The influence of pH (3 to 8), ionic strength (0 to 500 mM NaCl), and thermal treatment (30 to 90 °C) on the physical stability of the emulsions was examined. Extensive droplet aggregation occurred in WPI-stabilized emulsions around their isoelectric point (4pH6), at high salt (200 mM, pH 7), and at high temperatures (70 °C, pH 7, 150 mM NaCl), which was attributed to changes in electrostatic and hydrophobic interactions between droplets. There was little effect of pH, ionic strength, and temperature on emulsions stabilized by GA or MS, which was attributed to strong steric stabilization. In summary: WPI produced small droplets at low concentrations, but they had poor stability to environmental stress; GA produced large droplets and needed high concentrations, but they had good stability to stress; new MS produced small droplets at low concentrations, with good stability to stress. Practical Application: This study showed that stable rice bran oil-in-water emulsions can be formed using biopolymer emulsifiers. These emulsions could be used to incorporate RBO into a wide range of food products. We compared the relative performance of whey protein, GA, and a new MS at forming and stabilizing the emulsions. The new OSA MS was capable of forming small stable droplets at relatively low concentrations.

Brown rice has been reported to be more nutritious after germination. Germinated brown rice flours (GBRFs) from different steeping conditions (in distilled water [DI, pH 6.8] or in a buffer solution [pH 3] for either 24 or 48 h at 35 degrees C) were evaluated in this study. GBRF obtained from brown rice steeped at pH 3 for 48 h contained the highest amount of free gamma aminobutyric acid (GABA; 67 mg/100 g flour). The composite flour (wheat-GBRF) at a ratio of 70 : 30 exhibited significantly lower peak viscosity (PV) (56.99 - 132.45 RVU) with higher alpha-amylase activity (SN = 696 - 1826) compared with those of wheat flour (control) (PV = 136.46 RVU and SN = 1976). Bread formulations, containing 30% GBRF, had lower loaf volume and greater hardness (P < 0.05) than the wheat bread. However, the hardness of bread containing 30% GBRF (except at pH 6.8 and 24 h) was significantly lower than that of bread containing 30% nongerminated brown rice flour (BRF). Acceptability scores for aroma, taste, and flavor of breads prepared with or without GBRFs (30% substitution) were not significantly different, with the mean score ranging from 6.1 (like slightly) to 7 (like moderately). Among the bread formulations containing GBRF, the one with GBRF prepared after 24 h steeping at pH 3 had a slightly higher (though not significant) overall liking score (6.8). This study demonstrated that it is feasible to substitute wheat flour with up to 30% GBRF in bread formulation without negatively affecting sensory acceptance. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 30% germinated brown rice flour in a wheat bread formulation without negatively affecting sensory acceptance. In the current United States market, this type of bread may be sold as frozen bread which would have a longer shelf life. Further study is thus needed.

Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA.

Two glutinous rice-based snack formulations were designed using a linear-programming model to minimize total cost to meet the FAO/WHO/UNU. (1985). Energy and protein requirements . Report of a joint FAO/WHO/UNU expert consultation. Technical report series 724. Geneva: WHO requirements for lysine and sulphur amino acids. Effects of protein concentration, feed moisture content and barrel temperature on the chemical and physical properties of the extruded product were investigated. Response surfaces for the parameters were generated using a second-degree polynomial. The high protein nutritious snack was obtained using glutinous rice flour, vital wheat gluten and toasted soy grits. A factorial design was employed to investigate the influence of feed protein content (20 and 30 g/100 g wb), feed moisture (20, 25, and 30 g/100 g wb) and barrel temperature (150 and 180 °C) on the physical and chemical properties of extrudates. Results showed that increasing feed moisture and reducing barrel temperature reduced non-protein nitrogen (NPN) and enhanced lysine retention. The protein and moisture content of raw material and barrel temperature had no significant influence on cysteine and methionine content. The conditions providing high expansion, low bulk density, and low shear strength of extruded snack were feed moisture of 20 g/100 g wb and 180 °C.

Proving is one of the key processes in bread making, where dough normally rests and grows under an environment of constant temperature and humidity. To better understand the effect of relative humidity (RH) and temperature on the kinetics of dough expansion during proving and be able to optimize the growth rate, rice-flour-based dough of same formulation was proved under various process conditions. Both RH and temperature showed significant effect on the dough expansion rate during proving. To describe the dough expansion, a first-order, non-Arrhenius kinetic model was developed. The influence of RH and temperature on the kinetic rate was described by an empirical model. Through verification, the model performance was proved to be reasonably good. The model was subsequently used to optimize the proving condition to maximize the kinetic rate constant therefore minimizing the proving time. The fastest proving condition for the rice-flour-based dough in this research was at 90% RH and 46.3 °C. According to the model, the kinetic rate constant under the optimal condition was estimated to be at 0.217 min −1 . From an initial height of 5 mm, the dough height could be increased to 11 mm within 6.4 min.

The effects of blanching on physicochemical properties of flours and starches prepared from two varieties of sweet potatoes (Mun-Kai and Negro) were studied and compared. The pasting temperature and peak viscosity of starches, respectively, were 74 and 80 °C and 381 and 433 RVU. The pasting temperature (74.0-94.8 °C) of flours was greater than that of starch, depending on the variety and blanching process. However, the peak viscosity (ca. 103-120 RVU) of flours was lower than that of the corresponding starches. Partial gelatinization of starch granules was observed as a result of a 1-min blanching. Composition of starch and flour was found to affect swelling power and solubility. The starch content of starches, flours from unblanched sweet potato and flours from 1-min blanched sweet potatoes were 97; 66.3 and 74.9; as well as 36.6 and 40.4%, respectively. Amylose content of flours and starches varied from 17.2-20.8%.

Summary Soft starchy candy is a dessert with unique characteristics of thin sugar crust, soft internal texture and coconut milk flavour. Eight commercial samples were selected to represent commercially available products. Sensory liking were evaluated and analysed by preference mapping techniques. A lexicon consisting of 17 attributes was developed by a trained descriptive panel. Principal component analysis yielded four dimensions with 95.04% total variance explained. The product, having the highest liking scores in most of the sensory attributes evaluated, contained moisture and fat contents of 17.77% and 16.32%, respectively, which affected its aroma, flavour and texture. A significant relationship between sensory liking and some descriptive analysis attributes was observed. Sensory characteristics influencing overall liking were ‘coconut milk’ and ‘scented candle’ aroma and flavour, ‘hardness’ and ‘crust hardness’. This study revealed selected chemical composition and critical sensory attributes of soft starchy candy products that would help manufacturers develop acceptable products.