Padmanaban G. Krishnan

Bio: Padmanaban G. Krishnan is an academic researcher from South Dakota State University. The author has contributed to research in topics: Wheat flour & Gluten. The author has an hindex of 12, co-authored 40 publications receiving 501 citations.

Changes of isoflavones during processing of soy protein isolates

Abstract: Soy protein isolate (SPI) is a widely used food ingredient and is made by extracting soy flour (SF) under slightly alkaline pH, followed by precipitation, washing, and drying. Soy foods and foods containing soy protein ingredients have great potential in the prevention of cardiovascular diseases and cancers. These health benefits have been attributed to isoflavones in soy protein ingredients. However, the current processing techniques were developed many years ago without this knowledge. The objective of this study was to investigate the mass balance of different isoflavones during manufacturing of SPI and to provide basic information to assist further development efforts leading to preservation of soy isoflavones in soy protein ingredients. The study revealed that only about 26% of the total isoflavones in SF remained in SPI. The percentages of total isoflavones lost during extraction, precipitation, and washing were 19, 14, and 22%, respectively. Washing was the step where most isoflavones were lost. The isoflavone profile of the SPI was different from that of SF. The former contained much more aglucones (genistein and daidzein), while the latter had almost none. The high content of aglucones in SPI was probably due to the hydrolysis of glycosides.

Microstructural, textural, and sensory properties of whole-wheat noodle modified by enzymes and emulsifiers

Abstract: With the utilization of enzymes including endoxylanase, glucose oxidase (GOX) and transglutaminase (TG), and emulsifiers comprising sodium stearoyl lactate (SSL) and soy lecithin, the microstructural, textural, and sensory properties of whole-wheat noodle (WWN) were modified. The development time and stability of whole-wheat dough (WWD) were enhanced by TG due to the formation of a more compact gluten network, and by SSL resulting from the enhanced gluten strength. Microstructure graphs by scanning electron microscopy (SEM) verified that TG and SSL promoted the connectivity of gluten network and the coverage of starch granules in WWN. TG increased the hardness and elasticity of cooked WWN, while two emulsifiers increased the noodle cohesiveness. Additionally, TG and SSL improved the sensory properties of noodle such as bite, springiness, and mouth-feel. The results suggest that TG and SSL are effective ingredients in enhancing the gluten strength of WWD and improving the qualities of WWN.

Influence of processing conditions on apparent viscosity and system parameters during extrusion of distiller's dried grains-based snacks.

Abstract: A combination of different levels of distillers dried grains processed for food application (FDDG), garbanzo flour and corn grits were chosen as a source of high-protein and high-fiber extruded snacks. A four-factor central composite rotatable design was adopted to study the effect of FDDG level, moisture content of blends, extrusion temperature, and screw speed on the apparent viscosity, mass flow rate or MFR, torque, and specific mechanical energy or SME during the extrusion process. With increase in the extrusion temperature from 100 to 140°C, apparent viscosity, specific mechanical energy, and torque value decreased. Increase in FDDG level resulted in increase in apparent viscosity, SME and torque. FDDG had no significant effect (p > .5) on mass flow rate. SME also increased with increase in the screw speed which could be due to the higher shear rates at higher screw speeds. Screw speed and moisture content had significant negative effect (p < .05) on the torque. The apparent viscosity of dough inside the extruder and the system parameters were affected by the processing conditions. This study will be useful for control of extrusion process of blends containing these ingredients for the development of high-protein high-fiber extruded snacks.

Vegetable Oils in Food Technology: Composition, Properties, and Uses

Abstract: Preface to the First Edition. Preface to the Second Edition. Contributors. List of Abbreviations. 1 Production and Trade of Vegetable Oils ( Frank D. Gunstone ). 1.1 Extraction, refining and processing. 1.2 Vegetable oils: Production, consumption and trade. 1.3 Some topical issues. 2 Palm Oil ( Siew Wai Lin ). 2.1 Introduction. 2.2 Composition and properties of palm oil and fractions. 2.3 Physical characteristics of palm oil products. 2.4 Minor components of palm oil products. 2.5 Food applications of palm oil products. 2.5.1 Cooking/frying oil. 2.6 Nutritional aspects of palm oil. 2.7 Sustainable palm oil. 2.8 Conclusions. 3 Soybean Oil ( Tong Wang ). 3.1 Introduction. 3.2 Composition of soybean and soybean oil. 3.3 Recovery and refining of soybean oil. 3.4 Oil composition modification by processing and biotechnology. 3.5 Physical properties of soybean oil. 3.6 Oxidation evaluation of soybean oil. 3.7 Nutritional properties of soybean oil. 3.8 Food uses of soybean oil. 4 Canola/Rapeseed Oil ( Roman Przybylski ). 4.1 Introduction. 4.2 Composition. 4.3 Physical and chemical properties. 4.4 Major food uses. 4.5 Conclusion and outlook. 5 Sunflower Oil ( Maria A. Grompone ). 5.1 Introduction. 5.2 Sunflower oil from different types of seed. 5.3 Physical and chemical properties. 5.4 Melting properties and thermal behaviour. 5.5 Extraction and processing of sunflower oil. 5.6 Modified properties of sunflower oil. 5.7 Oxidative stability of commercial sunflower oils. 5.8 Food uses of different sunflower oil types. 5.9 Frying use of commercial sunflower oil types. 6 The Lauric (Coconut and Palm Kernel) Oils ( Ibrahim Nuzul Amri ). 6.1 Introduction. 6.2 Coconut oil. 6.3 Palm kernel oil. 6.4 Processing. 6.5 Food uses. 6.6 Health aspects. 7 Cottonseed Oil ( Michael K. Dowd ). 7.1 Introduction. 7.2 History. 7.3 Seed composition. 7.4 Oil composition. 7.5 Chemical and physical properties of cottonseed oil. 7.6 Processing. 7.7 Cottonseed oil uses. 7.8 Co-product uses. 8 Groundnut (Peanut) Oil ( Lisa L. Dean, Jack P. Davis, and Timothy H. Sanders ). 8.1 Peanut production, history, and oil extraction. 8.2 Oil uses. 8.3 Composition of groundnut oil. 8.4 Chemical and physical characteristics of groundnut oil. 8.5 Health issues. 9 Olive Oil ( Dimitrios Boskou ). 9.1 Introduction. 9.2 Extraction of olive oil from olives. 9.3 Olive oil composition. 9.4 Effect of processing olives on the composition of virgin olive oils. 9.5 Refining and modification. 9.6 Hardening and interesterification. 9.7 Quality, genuineness and regulations. 9.8 Consumption and culinary applications. 10 Corn Oil ( Robert A. Moreau ). 10.1 Composition of corn oil. 10.2 Properties of corn oil. 10.3 Major food uses of corn oil. 10.4 Conclusions. 11 Minor and Speciality Oils ( S. Prakash Kochhar ). 11.1 Introduction. 11.2 Sesame seed oil. 11.3 Rice bran oil. 11.4 Flaxseed (linseed and linola) oil. 11.5 Safflower oil. 11.6 Argan kernel oil. 11.7 Avocado oil. 11.8 Camelina seed oil. 11.9 Grape seed oil. 11.10 Pumpkin seed oil. 11.11 Sea buckthorn oil. 11.12 Cocoa butter and CBE. 11.13 Oils containing a-linolenic acid (GLA) and stearidonic acid (SDA). 11.14 Tree nut oils. Useful Websites. Index.

Molecular aspects of cereal β-glucan functionality: Physical properties, technological applications and physiological effects

Abstract: Cereals β -glucans are linear homopolysaccharides of consecutively linked (1→4)- β - d -glucosyl residues (i.e. oligomeric cellulose segments) that are separated by single (1→3)-linkages. β -Glucans display all the functional properties of viscous and gel forming food hydrocolloids combined with all the physiological properties of dietary fibres. This review focuses on the relationships between the molecular–structural characteristics of β -glucans and their physicochemical properties in aqueous dispersions and in food systems as well as their physiological functions in the gastro-intestinal tract. The physical properties of β -glucans, such as solubility and rheological behaviour in the solution and gel states, are controlled by their molecular features, such as their distribution of cellulosic oligomers, their linkage pattern and their molecular weight as well as by temperature and concentration. The technological and nutritional functionality of β -glucans is often related to their rheological behaviour. Incorporation of β -glucans into various products (bread, muffins, pasta, noodles, salad dressings, beverages, soups, reduced-fat dairy and meat products) showed that attributes, such as breadmaking performance, water binding and emulsion stabilising capacity, thickening ability, texture, and appearance appear to be related to the concentration, molecular weight and structure of the polysaccharide. The health benefits of β -glucans, such as reducing blood serum cholesterol and regulating blood glucose levels, are also correlated with the amount and molecular weight of the solubilised β -glucans in the gastro-intestinal tract.

Antioxidants in food : practical applications

Abstract: Part 1 Antioxidants and food stability: The development of oxidative rancidity in foods Inhibiting oxidation Measuring antioxidant activity. Part 2 Antioxidants and health: Cardiovascular disease and nutritional phenolics Antioxidants and anti-tumour properties Predicting the bioavailability of antioxidants in food: the case of carotenoids. Part 3 Natural antioxidants: Introducing natural antioxidants Sources of natural antioxidants: oilseeds, nuts, cereals, legumes, animal products and microbial sources Sources of natural antioxidants: vegetables, fruits, herbs, spices and teas. Part 4 Practical applications: Regulation of antioxidants in food Use of natural antioxidants in food products Preparation of natural antioxidants Natural antioxidant functionality during food processing.

Effect of dietary fibre on dough rheology and bread quality

Abstract: Dietary fibre is a common and important ingredient of a new generation of healthy food products demanded more each day by customers. Dietary fibre increases the nutritional value of bread but usually at the same time alters rheological properties of dough and, finally, the quality and sensorial properties of bread. The present work investigates the effect of some purified dietary fibres from different origins (orange, pea, cocoa, coffee, wheat and microcrystalline cellulose) on the rheological properties of wheat flour dough and the final quality of breads. The study of the rheological behaviour of the dough was performed by means of a consistograph and an alveograph. Bread quality was determined by means of texture, colour and specific volume measurements after baking under controlled conditions. The influence of fibre on bread sensory evaluation was established. Dietary fibre additions, in general, had pronounced effects on dough properties yielding higher water absorption, mixing tolerance and tenacity, and smaller extensibility in comparison with those obtained without fibre addition (in the control bread). Regarding the effect on bread properties, the fibre always enhanced the shelf life, as textural studies revealed. Sensory evaluations revealed that dietary fibres, with the exception of those from coffee and cocoa, can be added to flour at the level of 2% without deterioration of the bread palatability in comparison with white flour bread. Additions of 5% could imply the use of some additives to correct the rheological properties of dough.

Normal phase high-performance liquid chromatography method for the determination of tocopherols and tocotrienols in cereals.

Abstract: The eight vitamers of vitamin E (alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols) have different antioxidant and biological activities and have different distributions in foods. Some cereals, especially oat, rye, and barley, are good sources of tocotrienols. A fast procedure for the determination of tocopherols and tocotrienols (tocols) in cereal foods was developed. It involves sample saponification and extraction followed by normal phase high-performance liquid chromatography (HPLC). The results have been compared with those found by direct extraction without saponification. The method is sensitive and selective enough to be tested on a wide variety of cereal samples. The highest tocol levels were found in soft wheat and barley ( approximately 75 mg/kg of dry weight). beta-Tocotrienol is the main vitamer found in hulled and dehulled wheats (from 33 to 43 mg/kg of dry weight), gamma-tocopherol predominates in maize (45 mg/kg of dry weight) ), and alpha-tocotrienol predominates in oat and barley (56 and 40 mg/kg of dry weight, respectively).