Steady state flow behaviours of extruded blend of rice flour and soy protein concentrate

Rheological properties in terms of steady state flow behaviours of extruded dispersions (rice flour/soy protein concentrate blend), were investigated using dynamic rheometry. The effects of concentration (2%, 5%, 7%, 9% and 11%) and temperature (25–70 °C) on the rheological parameters (yield stress, flow behaviour index) of the non-expanded pellet blend (12.5% protein) were determined using common rheological models. Steady-shear viscosities in a range of shear rate from 0 to 500 s⁻¹ were observed as a function of concentration and temperature. From typical curves showing the dependence of shear stress on shear rate, it could be observed that all suspensions exhibited a non-Newtonian and pseudoplastic behaviour. The model that best fitted the experimental data at all temperatures and concentrations was the Herschel–Bulkley model.     

Extruded wheat flour: Correlation between processing and product quality parameters

The influence of independent processing parameters on the product properties of extruded mixtures of wheat flour and water has been investigated. Physical, chemical, and sensory measurements are reported and correlated with underlying processing parameters. Such correlation could be used to automate and control the extrusion process.     

Characteristics of low-fat meat emulsion systems with pork fat replaced by vegetable oils and rice bran fiber

The effects of vegetable oils prepared from olive, corn, soybean, canola, or grape seed, and rice bran fiber on the composition and rheological properties of meat batters were studied. Pork fat at 30% in the control was partially replaced by one of the vegetable oils at 10% in addition to reducing the pork fat to 10%. The chemical composition, cooking characteristics, texture properties, and viscosity of low-fat meat batters were analyzed. The moisture, protein, ash content, uncooked and cooked pH values, b^∗-value, hardness, cohesiveness, gumminess, chewiness, and viscosity of meat batters with vegetable oil and rice bran fiber were all higher than the control. In addition, batters supplemented with vegetable oil and rice bran fiber had lower cooking loss and better emulsion stability. Low-fat meat batters with reduced pork fat content (10%) and 10% vegetable oil plus rice bran fiber had improved characteristics relative to the regular fat control.     

Rheological and Thermal Properties of Extruded Mixtures of Rice Starch and Isolated Soy Protein

Many foods gain new mechanical, thermal and textural properties after being processed due to interactions between carbohydrates and proteins. This effect is characteristic for each foodstuff. The properties of extruded isolated soy protein (ISP) and rice starch were studied considering the following extrusion variables: starch proportion with respect to ISP (0–100%), pH (3–9), moisture content (20–30%) and temperature (140–180ºC). The following characteristics were measured: Water absorption index (WAI), water solubility index (WSI), glass transition temperature (T_g), melting temperature (T_m), viscosity at 90ºC and at 50ºC, storage (G′), loss modulus (G′′) and tan δ. The results indicate that the extruded starch exhibits higher WAI and WSI values than untreated starch. For extruded ISP these values are much lower than for untreated ISP. Extrudates with higher starch proportion had higher T_g and T_m values; pH has a significant effect (p<0.05), at pH 3 higher T_g values were observed, and at pH 9 higher values of T_m. The highest viscosities at 90ºC and 50ºC were observed for extrudates with a higher starch proportion and pH 9. Extruded mixtures showed a more elastic than viscous behavior and an extruded 1:1 blend of starch‐ISP exhibited the behavior of a viscous liquid.     

萌芽处理对鹰嘴豆粉营养成分及功能特性的影响

将鹰嘴豆进行不同时间萌芽处理,对带芽鹰嘴豆粉和无芽鹰嘴豆粉主要营养成分和功能性质进行研究。结果表明,萌芽处理可使鹰嘴豆粉淀粉含量有所下降、还原糖含量有所增加,蛋白质含量则是先小幅增加后又略微下降,而异黄酮含量增加显著,其中萌芽中含有远高于子叶的异黄酮含量。萌芽处理可显著提高鹰嘴豆粉的持水性、持油性和发泡能力,其中带芽豆粉好于无芽豆粉,但萌芽对乳化能力的影响不大。随着萌芽时间的延长,除萌芽24 h的鹰嘴豆粉粘度较高外,总体上豆粉的粘度呈快速降低趋势,豆粉的淀粉水解速率和最终葡萄糖生成量也相应下降,其中,豆粉中快消化淀粉含量明显降低而慢消化淀粉含量明显升高。对萌芽鹰嘴豆粉营养成分和理化特性的研究可以为萌芽鹰嘴豆食品的开发加工提供理论依据。     

燕麦研究进展

燕麦,一般分为带稃型皮燕麦和裸粒型裸燕麦两大类,燕麦营养成分包括蛋白质、脂肪、淀粉、膳食纤维、抗氧化物、维生素和矿物质等,现代营养学和医学研究表明,燕麦含有多种活性营养成分,具有降血脂、降血糖、减肥和美容等多种功能。目前有关燕麦研究主要集中在燕麦β-葡聚糖、蛋白、油脂等方面;该文主要讲述燕麦主要成分及其一些应用。     

燕麦麸蛋白质等电点测定及其稀碱法提取工艺优化的研究

燕麦蛋白具有很高的营养和保健价值,具有开发食疗保健型功能食品的潜能,开发前景广阔。以燕麦麸为原料,对其进行组成成分分析,结果表明:40～60目燕麦麸中蛋白质含量为19.42%、粗脂肪为10.57%、水分为7.74%、淀粉为49.54%、灰分为3.40%。并测定了燕麦麸蛋白质的等电点为pI=4.4。利用正交试验优化燕麦麸蛋白质稀碱法提取的工艺是料液比1∶10、pH11、60℃、浸提3h,在此条件下燕麦麸蛋白质的提取率是58.88%。     

Physicochemical and organoleptic characteristics of seasoned beef patties with added glutinous rice flour

This study was conducted to determine if glutinous rice flour (GRF) could be a functional food additive to potentially replace corn starch (CS), soy protein isolate (SPI) and/or sodium tripolyphosphate (STPP) to improve the physicochemical and organoleptic characteristics of seasoned beef patties. GRF had a lower cook loss among the treatment groups due to an increase in fat and moisture retentions (p<0.05). GRF lowered texture profile values for hardness, gumminess, springiness, and chewiness (p<0.05) of the patties, which are generally beneficial for this product. The beef patties with GRF were juicier and more tender than the control and other treatments (p<0.05). Hedonic scores for juiciness, tenderness and overall acceptability were the highest for the beef patties with 1 and 3% GRFs, suggesting that GRF may be an effective functional ingredient to improve the textural quality of seasoned beef patties.     

不同麸粉粒度及添加量对馒头品质和营养组分的影响

以小麦麸为原料,将其粉碎后添加到精粉中,并对添加麸粉的面粉制品(馒头)的营养组分进行了研究,旨在为改善粗纤维摄食量、增强人体健康提供一定数据参考。将粉碎后的小麦麸过80、120、200目筛,得到粒度不同的小麦麸粉。再分别将不同粒度的小麦麸粉按10%、20%、30%比例加入到特制一等粉中,制作麸粉含量不同的馒头,并对其进行理化指标的测定及感官评价。结果表明:过120目筛添加10%麸粉的样品中蛋白质及粗脂肪含量均最高,且与纯面粉含量有显著性差异(p<0.01);添加小麦麸粉后灰分含量均高于精粉。经感官指标和理化指标综合分析,过200目筛添加10%麸粉的馒头口感松软不粗糙、有浓郁的麦香味,且粗纤维的含量与空白相比呈极显著差异(p<0.001)。      

Potato flour as a functional ingredient in bread: evaluation of bread quality and starch characteristics

Potatoes have been added to bread for improvement of texture and moisture retention. The functional quality and starch digestibility in bread containing 5%, 10% or 15% potato flour were evaluated. Farinograph absorption of wheat and potato flour blends ranged from 59.0% to 77.7%. Bread with potato flour had significantly (P < 0.05) lower bread firmness during storage. There was a significant (P < 0.05) decrease in starch molecular weight as the level of potato flour increased. Inclusion of potato flour in these breads significantly (P < 0.05) increased the level of resistant starch (RS), while significantly (P < 0.05) decreasing the estimated glycemic index (eGI). Bread with no potato flour had 5.2% RS and an eGI of 95, while the bread with 15% potato flour had 11.3% RS and an eGI of 87. Overall, the addition of potato flour may reduce dough strength and loaf volume, but it reduced staling and increased resistant starch content of the bread.     

Characterisation of oat bran products with and without supercritical carbon dioxide extraction

Morphology, starch structures and thermal and pasting properties of oat bran concentrate (OBC) and Nutrim‐OB (NOB), a jet‐cooked oat bran product, with or without supercritical carbon dioxide extraction (SCD) were studied. Oil composition was analysed. OBC had three thermal transitions, starch gelatinisation and two amylose–lipid complex transitions. NOB only had amorphous amylose–lipid transition. SCD significantly decreased gelatinisation temperatures of OBC. Pasting properties, showed NOB had significantly higher peak viscosity and breakdown, with significantly lower final viscosity, setback and pasting temperature compared with OBC. SCD increased peak viscosity for NOB and final viscosity for OBC. Thermogravimetric analysis showed NOB had higher water‐holding capacity (WHC) than OBC, while SCD decreased WHC. Amylopectin molecular weight was 3.4 × 10⁸ for OBC and was significantly lower for NOB (1.4 × 10⁸). Predominant fatty acids were oleic (41%), linoleic (38%) and palmitic (16%). Study showed NOB had different properties from OBC thereby expanding industrial applications.     

Effect of proteins on the formation of starch–lipid complexes during extrusion cooking of wheat flour with the addition of oleic acid

The formation of starch–lipid complexes plays an important role in extruded products. The effect of gluten proteins on thermal conditions at which the starch–lipid complexes formed during extrusion cooking of wheat flour with the addition of oleic acid was evaluated, considering wheat starch as a reference. The presence of gluten proteins in wheat flour extrudates brought about a reduction of the formation of starch–lipid complexes compared to blend of wheat starch and oleic acid extruded at the same operating conditions (melting enthalpy: 0.4 vs. 1.6 kJ kg^?1). Moreover, the lubricant effect of oleic acid observed during extrusion of wheat starch (low values of specific mechanical energy and residence time) was not found during extrusion of wheat flour with addition of oleic acid because of the interaction between gluten proteins and oleic acid. This research points out the importance of proteins on biopolymer modifications and their effect on extrudate quality.     

Effects of glutinous rice flour on the physiochemical and sensory qualities of ground pork patties

The study investigated the effects of glutinous rice flour (GRF) on the quality of ground pork patties. Ground pork patties with 3% of GRF showed better quality compared to addition of 1% and 5% of GRF. Addition of 3% GRF was further compared with 0.5% carrageenan, 3% soy protein isolate, 3% corn starch and 3% potato starch in ground pork patties. The cooking yield in GRF group was significantly higher than that of other treatments due to the increase in moisture and fat retentions (P < 0.05). Comparing with other groups, GRF showed lower texture profile values for hardness and chewiness (P < 0.05). The ground pork patties with GRF were juicier, more tender and showed better flavor and overall acceptability compared to control and the treatments with other additives (P < 0.05). The results indicate that GRF could be an effective functional ingredient in ground pork patties.     

Extrusion of soy protein with gelatin and sugars at low moisture content

Soy protein-based materials modified with gelatin, lactose and sucrose were prepared by extrusion at low moisture content. The effect of composition on the extrusion parameters was investigated and specific mechanical energy (SME) was measured as an indication of extrusion processability, thus providing good characterization of the extrusion process in order to make it highly energy efficient and cost effective. Water content was the most important factor on the extrusion parameters and product properties. The incorporation of gelatin increased SME and the product obtained at the extruder die was not continuous. However, when lactose was added, SME decreased and the color of the product changed due to Maillard reaction. This reaction could be analyzed by Fourier transformed infrared spectroscopy (FTIR) where the changes of the amide I and amide II bands reflected that hydroxyl groups in sugars and amino groups in soy protein isolate (SPI) were consumed during extrusion. These results are in good agreement with total soluble matter (TSM) values, which were lower for mixtures with lactose than sucrose due to a higher degree of Maillard reaction. Moreover, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results also showed the influence of Maillard reaction, which lead to more ordered and compact structures, respectively.     

Effect of enrichment with hemicellulose from rice bran on chemical and functional properties of bread

This paper examines the use of the defatted rice bran hemicellulose B (RBHB), and insoluble dietary fibre (RBDF), as two functional ingredients added to bakery products. The results show that the RBHB from defatted rice bran had high water-binding and swelling capacity. RBHB exhibited high fat binding capacity. However, RBHB was found to be low viscous. Addition of 1%, 2% and 3% RBHB preparation reduced loaf volume significantly and increased the firmness of the breads. Sensory evaluations revealed that breads with 1%, 2%, 3% RBHB and 2%, 4% RBDF were overall acceptable. This confirms that the RBHB and RBDF preparation from defatted rice bran has great potential in food applications, especially in development of functional foods including functional bakery products.     

Optimization of replacing pork back fat with grape seed oil and rice bran fiber for reduced-fat meat emulsion systems

The effects of reducing pork fat levels from 30% to 20% and partially substituting the pork fat with a mix of grape seed oil (0%, 5%, 10% and 15%) and 2% rice bran fiber were investigated based on chemical composition, cooking characteristics, physicochemical and textural properties, and viscosity of reduced-fat meat batters. For reduced-fat meat batters containing grape seed oil and rice bran fiber the moisture and ash contents, uncooked and cooked pH values, yellowness, cohesiveness, gumminess, chewiness, and sarcoplasmic protein solubility were higher than in the control samples. The reduced-fat samples with increasing grape seed oil concentrations had lower cooking loss, emulsion stability, and apparent viscosity. The incorporation of grape seed oil and rice bran fiber successfully reduced the animal fat content in the final products while improving other characteristics.     

Effects of protein–lipid and starch–lipid complexes on textural characteristics of extrudates based on wheat flour with the addition of oleic acid

The knowledge of biopolymer changes by extrusion is very important for a wide range of industrial applications that spreads from extruded food to biodegradable packaging. In this article, the formation of starch–lipid and lipid–protein complexes that occurred during the extrusion cooking of wheat flour with the addition of fatty acids was studied. Results showed that the highest barrel temperature (128.3 °C) promoted the formation of starch–lipid complexes in samples made up of wheat starch and wheat flour with the addition of fatty acids. The maximum formation of protein–lipid complexes (68% fatty acid bound to protein) was observed at the highest barrel temperature and water feed content (<22%). This study is a prerequisite for the optimisation of production of expanded extrudates made up of wheat flour and fatty ingredients and for the study of a biodegradable packaging based on by‐product of milling wheat (and fat).     

Sensory,functional characteristics and in vitro digestibility of snacks supplemented with non-traditional ingredient raw and processed fenugreek

Fenugreek seeds were germinated, soaked and roasted and were evaluated for nutritional properties. Raw and processed fenugreek seeds were used to develop snack product. Snacks were examined for the sensorial, functional, antinutritional properties and in vitro digestibility. Using sensory analysis, 5% level of substitution of raw and processed fenugreek was accepted for the development of extruded snacks. Lateral expansion was highest for snacks prepared from processed fenugreek (163.0% to 206.1%) than raw fenugreek (162.5 to 168.7%), and vice versa for bulk density. The antioxidant activity and total phenolic content were highest for snacks prepared from germinated fenugreek (7.30% to 9.87% and 1.352 to 3.561 mg GAE g⁻¹ of sample) and lowest for snacks prepared from raw fenugreek (6.68% to 7.03% and 1.29 to 2.76 mg GAE g⁻¹ of sample). Not only extrusion but also processing such as soaking, roasting and germination reduced the antinutritional content of the snack product. Both in vitro digestibilities increased with extrusion cooking. In vitro digestibility was also found to be higher in snacks prepared from processed fenugreek than raw fenugreek. Therefore, development of such functional foods using processed fenugreek would raise the consumer demand and benefit the population by increasing the health status.