Influence of Flour Particle Size on Quality of Gluten-Free Rice Cakes

There is a growing interest in developing gluten-free bakery products in recent time. In cake making, gluten network formation is not essential, but hardly any information exists about the influence of the gluten-free flour characteristics affecting the final cake product. This study analyses the influence of two different rice cultivars (short and long) with different flour particle size in batter characteristics (specific volume, viscosity and internal structure) and in sponge and layer cake formulas (volume, shape, texture and colour). During starch gelatinization, the finest flours (median particle size finer than 100 μm) increased their viscosity and reached the peak viscosity (RVA) later than the coarsest flours. Moreover, the finest flours gave batters with lower specific volumes but with an air distribution in smaller and uniform bubbles in both formulas. These flours also produced higher volume and lower firmness in sponge cakes and greater symmetry index both in sponge and layer cakes. The rice type also influenced batter and cakes characteristics but in a lesser extent. The different results obtained depending on the rice flour particle size, type flour and cake formulation indicate the need to define them both in industrial specifications and in research studies.     

Functional Characterization of Steam Jet-Cooked β-Glucan-Rich Barley Flour as an Oil Barrier in Frying Batters

ABSTRACT:  The effect of steam jet-cooking on the hydration, pasting, and rheological properties of barley flour was investigated. The thermo-mechanical shear during steam jet-cooking led to significant increases in the water absorption, water solubility, and swelling power of the barley flour. Also, the pasting profile showed elevated initial viscosity and reduced final viscosity. In addition, the suspensions of the steam jet-cooked barley flour demonstrated typical shear thinning and dynamic viscoelastic responses of random coil polysaccharides with entanglements. The steam jet-cooked barley flour was also evaluated as an oil barrier in fried foods. Its incorporation into frying batters increased batter pickup and viscosity while the moisture loss of fried batters was reduced. These combined effects significantly lowered the oil uptake of batters.     

Relationship between Rice Flour Particle Sizes and Expansion Ratio of Pure Rice Bread

We examined a method to produce bread from crystalline rice flour without using thickening agents such as gluten, polysaccharide thickening, and amorphous rice flour. Rice grains were pulverized by a jet mill to produce flour. Samples of rice flours of various particle size distributions were prepared by using a size shifter. The degree of starch damage and the dynamic viscoelasticity of rice batter were measured in this work. We also baked bread of the flour of each size distribution to study processability for making bread. The batter made by the pulverized flour of rice particle size ranging from 75 to 106 μm had the highest expansion ratio and a good processability for baking breads compared to other particle size batters. The rice bread with high expansion ratio was produced by controlling particle size of crystalline rice flour without using thickening agents.     

Machine learning workflow for the oil uptake prediction of rice flour in a batter-coated fried system

Machine learning algorithms were applied to predict the oil uptake of rice flour in batter-coated fried foods, depending on its physicochemical features before frying (amylose content, pasting parameters, and batter viscosity). Low coefficients of Pearson correlation (0.29–0.61) were observed between the oil uptake of rice frying batters and other physicochemical parameters. Based on an exhaustive search method by the regsubsets function, the four experimental features (amylose content, peak time, peak temperature, and final viscosity) were selected as the best subset to affect the oil uptake of rice batters after frying, and then subjected to two machine learning algorithms – multivariable linear regression and multilayer perceptron neural network. Based on K-fold cross-validation, the experimental results were divided into 5 datasets consisting of each 80% training and 20% testing dataset. Compared to the multivariable linear regression (R² = 0.6204–0.7219), the iterative application of the multilayer perceptron model made a relatively higher prediction (R² = 0.7388–0.7781) of the oil uptake of rice flour frying batter. Thus, the multilayer perception model with a hidden layer outperformed the multivariable linear regression by showing higher R² and lower relative error.     

Food components affecting the oil absorption and crispness of fried batter

Frying batters are used to add value to a product by improving texture, flavour, weight and volume and reducing water loss during frying which, in turn, lessens oil absorption. The physical characteristics of fried batters were studied using model systems based on rice flours. Crispness was positively correlated with amylose content, while oil absorption was negatively correlated with amylose content. Addition of pregelatinised rice flour improved crispness but resulted in increased oil absorption because of the porous nature of the fried product. Amongst the proteins (egg yolk, gluten, skimmed milk, whey and ovalbumin) studied, ovalbumin was able to reduce oil absorption and improve the crispness of the fried batter. Addition of calcium chloride also reduced oil absorption and improved crispness, while a little oil reduced the oil content of the fried batter and improved its taste. Addition of ovalbumin, oil or calcium chloride beyond the optimal levels reduced crispness and increased oil absorption in a linear manner. Modified tapioca starch and diglyceride emulsifiers improved crispness but increased oil absorption. The amount of water added to the formulation affected the physical characteristics of the fried batter. The optimal formulation for a crisp frying batter with reasonably low oil absorption was an amylose/amylopectin ratio of about 18: 67; with (g kg⁻¹) 850 pregelatinised rice flour; up to 150 modified tapioca starch; 30 ovalbumin; 1 calcium chloride; 20 oil; 20 emulsifier and a water/flour ratio of 2:1. © 1998 Society of Chemical Industry.     

Cross-linking of wheat starch improves the crispness of deep-fried battered food

Wheat starches with different degrees of cross-linking were used to study the effect of starch gelatinization in the batter and crust characteristics of deep-fried battered food. Pasting properties, viscosity and batter pick up as well as moisture and oil content and crispness of the fried crusts were evaluated. In batters prepared with a constant solids/water ratio, the cross-linked starches increased batter viscosity and consequently the batter pick up. Batters, with comparable viscosity were prepared by varying the solid/water ratio which gave the same batter pick up.The pasting properties of cross-linked starches showed that the higher the cross-linking the more resistant was the starch to gelatinization and granule disintegration. In batters with a constant solids/water ratio, batter with high cross-linked starch had more water loss during frying. Cross-linked starches had lower moisture content after storage and less oil was retained after frying. Crispness, measured instrumentally as sound intensity, was the highest for the high cross-linked starch at 1 and 20 min after frying.Batters prepared with the same viscosity were used to study the effect of cross-linked starches when the pick up was the same. To obtain comparable viscosities between the batters, the batter with native starch was prepared using the lowest mixing water content and the one with high cross-linked starch with the highest. The batter with the high cross-linked starch, although it had the highest addition of water, had the best crispness after frying.In conclusion, high cross-linking of wheat starch enhances crispness perception of deep-fried battered food.     

Effect of Hydroxypropyl Methylcellulose on Rheological Properties, Coating Pickup, and Oil Content of Rice Flour-Based Batters

Rice flour-based batter is an alternative for wheat flour-based batter for consumers with wheat allergy or wheat intolerance. Further advantage of rice flour in batter is its ability to reduce oil uptake. However, due to its low-protein content, high amylose, and small granule size, rice flour-based batter possesses poor adhesion property. The aim of this study was to investigate the effect of the addition of hydroxypropyl methylcellulose (HPMC); a hydrocolloid, on rheological properties, coating pickup, and oil absorption of HPMC-rice-based fried batter. Rheological properties of rice flour-based batters containing HPMC with different degrees of substitution (DS) and concentrations were determined. In steady-shear measurements, the addition of HPMC; E4M (DS = 1.9) and K4M (DS = 1.4), led to the increase of apparent viscosity, yield stress, and consistency index. K4M rice flour batters showed shear-thickening behavior (n > 1) with syneresis. HPMC increased the complex modulus (G*) of batters, where storage moduli (G′) were higher than loss moduli (G″). The crossover points increased with increasing HPMC concentration. HPMC addition increased the coating pickup of fresh carrot sticks and less coating loss was observed with K4M. Rice batter formulated with 0.5% E4M provided deep-fried crust with 26% lower oil content compared to the control crust.     

Effect of enzymatic treatments on the rheological and oil-resisting properties of wheat flour-based frying batters

A new enzymatic approach was introduced to reduce the oil uptake of batter-coated fried foods. Cross-linking (transglutaminase) and cell wall-degrading (viscozyme) enzymes were incorporated into the formulation of wheat flour-based frying batters, and their rheological/oil-resisting effects were evaluated. The transglutaminase treatment increased the pasting viscosities of wheat flour whereas viscozyme distinctly reduced these properties. The batters treated with transglutaminase exhibited the highest steady-shear viscosity, followed by the control and viscozyme-treated samples. Dynamic viscoelastic results showed that transglutaminase improved the elastic properties of frying batters, while their viscous characteristics became more dominant when viscozyme was used. These rheological features were favorably correlated with the adhesive properties of batters. During frying, the moisture loss of frying batters was retarded by transglutaminase. The incorporation of transglutaminase reduced the oil uptake of frying batters by 19.6%, thus contributing to the enhancement of the oil-barrier property.     

Porosity determination of deep‐fat‐fried coatings using pycnometer (Fried batter porosity determination by pycnometer)

The effect of processing conditions such as frying time and temperature, and batter formulation on pore development in deep‐fat fried chicken nuggets coatings were studied using helium pycnometer method. Chicken nuggets with preformed and laboratory prepared batter coatings were fried at temperatures between 170 and 190 °C for a time range between 0 and 240 s. There was significant (P < 0.05) effect of frying temperature and batter formulation on porosity. Porosity increased with frying time and temperature, and ranged between 2.15 and 47.92% for the preformed batter and 9.96 and 54.76% for the formulated batters. Apparent and bulk densities of the preformed batters increased and decreased with frying time, respectively, but both declined gradually with increasing frying temperature. As the level of rice flour in the formulation increased, apparent and bulk densities also increased. Batter formulation and frying temperature significantly (P < 0.05) influenced the variation in moisture and fat content of the fried batter. Porosity demonstrated positive and negative correlation with fat uptake and moisture loss, respectively, for all the batter coatings.     

不同热处理的米粉对小麦粉裹粉特性的影响

以信阳杂交早粳米和小麦粉为原料,通过挤压膨化和湿热调质的方法对米粉进行热处理,对比研究这2种热处理米粉对小麦粉裹粉性质影响,探索不同添加量热处理米粉对小麦粉裹粉品质的改良作用,旨在为裹粉工业的发展提供依据。结果显示:添加热处理米粉可以提高小麦粉裹粉吸水性指数、膨润力、挂糊量、含水量、脆度和感官评分,降低峰值黏度、低谷黏度、崩解值、最终黏度和回生值的作用。相关性分析表明,裹粉的挂糊量与热处理米粉添加量呈显著正相关关系,而糊化特性和感官评分与热处理米粉添加量呈显著负相关关系,对于水溶性指数、膨润力、含水量、含油量和脆度与热处理米粉添加量相关性不一致,这2种热处理米粉均改善了裹粉的品质。     

Effects of pre-heating temperature and formulation on porosity,moisture content,and fat content of fried batters

The effect of pre-heating temperatures on moisture and fat contents, and porosity of fried batters was studied. Batter pre-heated at 60 °C showed higher moisture content, lower fat content and lower porosity than non-pre-heated batter and batters pre-heated at 70 and 80 °C. Moisture content, fat content, and porosity at 4 min frying for batters with different pre-heating treatments ranged from 35.08 to 39.37, 3.92 to 5.16, and 13.14 to 45.31 %, respectively. Because of significant reduction in fat content, 60 °C pre-heating temperature was chosen to study the effect of batter formulations on moisture and fat contents, and porosity. Different wheat to rice flour ratios were prepared, and then each batter was pre-heated at 60 °C. Batters with higher wheat flour content showed higher moisture content, and lower fat content and porosity than batters with higher rice flour.     

INFLUENCE OF METHYLCELLULOSE ON OIL ABSORPTION OF WHEAT FLOUR BATTER COATED CUT POTATOES1

The influence of substitution types (A4M, E4M, and K4M), molecular weights (14000, 41000, and 86000), and concentrations (0, 0.2, 0.4, and 0.6% w/w of flour) of methylcellulose on oil absorption of wheat flour batter-coated cut potatoes in two batter systems was studied. The two batter systems are (1) controlled viscosity batters at 1200 cp (CVB) and (2) controlled initial moisture content batters at 134 g/100 g flour (CIMB). In CVB, addition of methylcellulose increased initial moisture content of batters. There was no significant difference in moisture and oil content in fried products among types of methylcellulose. Higher number average molecular weight (Mn) of methylcellulose up to 41000 with simultaneous increase in initial moisture content resulted in greater moisture content in fried coating and oil content in food substrate. The higher the concentration of methylcellulose with concurrent increase in initial moisture content of batter, the greater the oil content in food substrate and the lower the oil uptake ratio in coating were obtained. For CIMB, addition of methylcellulose raised viscosity of batters. Higher Mn and concentration of methylcellulose in CIMB provided increasing coating thickness and decreasing oil uptake in fried products. Substitution type of methylcellulose for the molecular weight studied did not affect the fried quality whereas increase in Mn and concentration resulted in lower oil absorption and oil uptake ratio.     

Effects of batters containing different protein types on the quality of deep-fat-fried chicken nuggets

The effects of soy protein isolate (SPI), whey protein isolate (WPI) and egg albumen (EA) on the quality of deep-fat-fried chicken nuggets were studied. Batter without protein addition was used as a control. Batter pickup and moisture content, oil content, texture, porosity and colour of the nuggets were determined for 3, 6, 9 and 12 min of frying at 180 °C. Additionally, the rheological properties of batters were studied. SPI (3%) provided the highest apparent viscosity and coating pickup. All the batters showed shear-thinning behaviour except EA-added batter. Addition of different proteins to the batter formulation decreased the oil content of the final product. EA reduced the oil content of chicken nuggets significantly but yielded softer products. WPI (3%) was found to be the most effective ingredient on improving quality parameters of deep-fat-fried chicken nuggets. WPI (3%) added batters provided the hardest and crunchiest product with the darkest colour and also significantly reduced the oil content of the fried nuggets.     

Acrylamide formation in different batter formulations during microwave frying

Acrylamide, a probable human carcinogen, is found to be formed in a wide range of fried foods. In this study, the effects of microwave frying on acrylamide formation in the coating part of chicken were investigated. It was also aimed to determine the effects of various flour types (soy, chickpea and rice flour) in batter formulations on the acrylamide formation and on the color of fried chicken. Usage of all flour types except soy flour resulted in approximately the same moisture content and color development after 1.5 min of microwave frying. Acrylamide contents of batter parts of 1.5 min microwave fried samples having different flours were similar. Microwave frying provided lower acrylamide content and lighter color as compared to those fried conventionally for 5 min for all types of flours. This reduction in acrylamide level was the highest (34.5%) for rice flour containing batter.     

Functionality of batters containing different starch types for deep-fat frying of chicken nuggets

The effect of various starch types (amylomaize, corn, waxymaize, pregelatinized tapioca) on quality attributes (texture, moisture content, oil content, color, coating pick up, cooking yield, volume and porosity) of deep-fat fried chicken nuggets were studied. Chicken samples, 0.04 m in diameter and 0.015 m in thickness, taken from the breast portion, were coated with batters composed of a 3:5 solid to water ratio by immersion. The solid content of batter formulations contained equal amounts of corn and wheat flour, 5.0% starch, 1.0% salt and 0.5% leavening agent. As control, batter without starch addition, was used. Samples were fried at 180°C for 3, 6, 9 and 12 minutes. Crispness and oil content of chicken nuggets increased, whereas moisture content decreased with increasing frying time. Starch addition to the formulations increased crispness of the product significantly at the last stages of frying. The highest porosity and oil content was obtained when corn starch was used. Pregelatinized tapioca starch was found to provide a product with the lowest oil content, the highest moisture content, coating pick up and volume.     

Thermal properties of batter systems formulated by combinations of different flours

There is an increasing consumer preference for reduced oil content in fried food products. The amount of fat absorbed by deep fried foods can be modified using appropriate coatings such as batter and breading systems. Coatings also change the heat transfer characteristics of the composite products. The goal of this study was to determine some thermal properties of selected batter mixes that are commonly used for deep fat frying of chicken products. Three types of flour-based batter mixes were used. These were mixtures of wheat and rice (WR), wheat and corn (WC), and corn and rice (CR) flours with salt and different methylcellulose (MC) levels. The differential scanning calorimeter (DSC) was used to measure glass transition temperature (T_g), gelatinization temperature (T_G), ice-melting temperature (T_m) and enthalpy (ΔH_G) of the different batter formulations. Salt and MC greatly influenced the thermal properties of batter systems as they increased T_G, but depressed T_m. Adding rice and corn flours to wheat flour based batters apparently changed the thermal properties. Corn flour based batters required considerable more energy for gelatinization during the cooking process.     

Effect of an oat beta-glucan-rich hydrocolloid (C-trim30) on the rheology and oil uptake of frying batters

ABSTRACT:  C-trim30, a new β-glucan-rich hydrocolloid containing 32%β-glucan, was obtained by steam jet-cooking and fractionating oat bran concentrates. It was then incorporated into batter formulations to investigate the rheological effects of C-trim30, which were correlated with batter attributes. In steady shear measurements, the use of C-trim30 led to the increase in batter viscosity, while it did not show significant effects on the shear-thinning pattern of batters. Moreover, the increase in the dynamic viscoelastic properties was observed with more contribution to elastic properties because of the high water-holding properties of C-trim30. These rheological characteristics could be correlated with the adhesive properties of batters to a food matrix. In addition, C-trim30 was shown to produce a sample with increased batter pickup, less moisture loss, and reduced oil content. Even, the oil content was reduced by up to 40% when 4% C-trim30 was used in the batter formulations. The combined effects of elevated viscosity, great batter pickup, and reduced moisture loss by the use of C-trim30 contributed synergistically to the reduction of oil content in fried foods.     

Effects of Rice Batter on Oil Uptake and Sensory Quality of Coated Fried Okra

ABSTRACT: Okra was coated and deep-fat fried with batters of flour sources including rice flour, a mixture of rice flour and small amounts of pregelatinized rice flour (PGRF), and, as a control, traditional wheat flour. The addition of PGRF, up to 8%, enhanced batter viscosity and the coating properties of the rice batter. Oil uptake of the fried batter decreased with the addition of up to 5% PGRF. Rice flour fried batters, with and without PGRF, were found to absorb substantially lower oil, by as much as 51 %, compared with the wheat batter. The fried okra coated with the rice batter containing 5% PGRF, when evaluated for sensory properties on appearance and surface attributes, was found to be superior or equal to those with the wheat batter and rice batter without PGRF. Particularly, its golden brown color is considered more desirable than the lighter yellow color of the other 2 entities. Similarly, most of its 1st-bite and after-chew properties were slightly better and were in the normal range of commercially available products. Specifically, its distinctive crispiness is considered a positive attribute, whereas its slightly higher tooth packing properties, while remaining in the range of commercial products, may be noticeable to some consumers.     

Effects of beer‐battering on the frying properties of rice and wheat batters and their coated foods

BACKGROUND: Beer in batter formulation or beer‐battering has been popular in fried food recipes, but the topic is rarely reported in scientific journals or the claims substantiated with reliable studies. In this research, we prepared and characterized rice and wheat batters with and without using beer to replace water in the formulation. We studied and provided data on the effect of beer on the frying properties of batter and its coated foods. RESULTS: With beer in the formulation, oil uptake of fried batters generally increased by up to 18%. Instrumental textural analyses indicate that beer‐battering treatment generally decreased the hardness, increased the fracturability and improved the crispness of the fried batters. Sensory evaluations show similar trends, though to a lesser extent, that fish and onion rings coated with batters were softer but crispier with beer than without. CONCLUSION: In general, beer‐battering caused an increase in the oil uptake of the batter during frying. It also made the texture of fried batters slightly softer and crispier. The effects are more pronounced for rice batters than wheat batters. Copyright © 2010 Society of Chemical Industry     

Effects of Soy and Corn Flour Addition on Batter Rheology and Quality of Deep Fat-Fried Shrimp Nuggets

In this paper, the effects of soy and corn flour (5 and 10% w/w) addition to the batter formulation on the quality of deep fat-fried shrimp nuggets were evaluated. Rheological properties of batters, coating pick-up, moisture content, and oil content of the samples were determined. Shrimp nuggets were fried at 150 °C, 170 °C, 190 °C, for 1, 2, 3, 4, and 5 min. The coating pick-up, oil and moisture content were found to be directly proportional to batter viscosity. All batters were found to show shear thinning behavior by exhibiting flow behavior index ≤ 1. The batters were modeled as power law fluids. Batter formulation, frying time, and temperature significantly (p < 0.01) affected moisture and oil content of shrimp nuggets. Soy flour added batters provided the highest consistency index, 7.595 and 10.635 Pa.sⁿ for 5% and 10% soy flour added, respectively. Soy flour was found to be an effective ingredient in decreasing oil content of fried nuggets. Batters containing 5% corn flour showed the lowest moisture content and the highest oil content among all the formulations. The mean moisture and fat content of shrimp nuggets coated with batter contained 10% soy and 5% corn flour, fried at 190 °C, for 5 min were 0.59 ± 0.022, 0.480 ± 0.029 and 0.149 ± 0.035, 0.346 ± 0.024 (g/g db), respectively.