Department Of Applied Agriculture

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Author: search.filters.author.Kaur, Amritpal

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    Enzymatic Browning of Fruit and Vegetables: A Review
    (Springer, 2018) Kanchan, Balwinder Singh; Suri, Kanchan; Shevkani, Khetan; Kaur, Amritpal; Kaur, Amarbir; Singh, Narpinder
    Enzymatic browning in fruits and vegetables occurs by exposure to the air after cutting and slicing and in pulped states, mechanical damage during transportation, and thawing of frozen or cold stored foods. Polyphenol oxidase (PPO) and peroxidase (POD) are the main enzymes responsible for browning. PPO is classified as an oxidoreductase enzyme with four atoms of copper as a prosthetic group. It catalyzes the oxidation of functional OH group attached to the carbon atom of the benzene ring of monohydroxy phenols (phenol, tyrosine, p-cresol) to o-dihydroxy phenols (catechol, dopamine, adrenalin) and dehydrogenation of o-dihydroxy phenols to o-quinones. The oxidation of phenolic compounds to quinones and production of melanin give rise to a dark color in the foods. The POD is thermostable enzyme that belongs to a group of oxidases that use H2O2 as a catalyst for oxidation of phenolic compounds. The POD is related to undesirable changes in flavor, texture, color, and the nutritional quality of foods. The level of PPO and POD varies in fruits and vegetables and their content changes with maturity and senescence depending upon the ratio of bounded and soluble enzymes. Change in color of fruits and vegetables by enzymatic reactions is a major problem during harvesting, transportation, storage, and processing. Color deterioration, off-flavor, and loss of nutritive value in foods are unacceptable to the consumers. The purpose of this chapter is to provide information available in the literature on PPO and POD in different fruits and vegetables, their role in browning/color changes, and available prevention methods.
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    Wheat starch production, structure, functionality and applications-a review
    (Blackwell Publishing Ltd, 2017) Shevkani, Khetan; Singh, Narpinder; Bajaj, Ritika; Kaur, Amritpal
    Starch is the main component of wheat having a number of food and industrial applications. Thousands of cultivars/varieties of different wheat types and species differing in starch functionality (thermal, retrogradation, pasting and nutritional properties) are grown throughout the world. These properties are related to starch composition, morphology and structure, which vary with genetics, agronomic and environmental conditions. Starches from soft wheat contain high amounts of surface lipids and proteins and exhibit lower paste viscosity, whereas that from hard cultivars contain high proportion of small granules and amylose content but lower gelatinization temperature and enthalpy. Waxy starches exhibit higher-percentage crystallinity, gelatinization temperatures, swelling power, paste viscosities and digestibility, but lower-setback viscosity, rate of retrogradation and levels of starch lipids and proteins than normal and high-amylose starches. Starches with high levels of lipids are less susceptible towards gelatinization, swelling and retrogradation and are good source of resistant starch, while that with high proportion of long amylopectin chains are more crystalline, gelatinize at high temperatures, increase paste viscosity, retrograde to a greater extent and decrease starch digestibility (high resistant and slowly digestible starch and low rapidly digestible starch).
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    Wheat starch production, structure, functionality and applications :a review
    (Blackwell Publishing Ltd, 2017) Shevkani, Khetan; Singh, 2 Narpinder; Bajaj, Ritika; Kaur, Amritpal
    Starch is the main component of wheat having a number of food and industrial applications. Thousands of cultivars/varieties of different wheat types and species differing in starch functionality (thermal, retrogradation, pasting and nutritional properties) are grown throughout the world. These properties are related to starch composition, morphology and structure, which vary with genetics, agronomic and environmental conditions. Starches from soft wheat contain high amounts of surface lipids and proteins and exhibit lower paste viscosity, whereas that from hard cultivars contain high proportion of small granules and amylose content but lower gelatinization temperature and enthalpy. Waxy starches exhibit higher-percentage crystallinity, gelatinization temperatures, swelling power, paste viscosities and digestibility, but lower-setback viscosity, rate of retrogradation and levels of starch lipids and proteins than normal and high-amylose starches. Starches with high levels of lipids are less susceptible towards gelatinization, swelling and retrogradation and are good source of resistant starch, while that with high proportion of long amylopectin chains are more crystalline, gelatinize at high temperatures, increase paste viscosity, retrograde to a greater extent and decrease starch digestibility (high resistant and slowly digestible starch and low rapidly digestible starch). ? 2016 Institute of Food Science and Technology
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    Effect of degree of milling on physicochemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars
    (Elsevier Ltd, 2018) Sandhu, Rubrinder Singh; Singh, Narpinder; Kaler, R.S.S.; Kaur, Amritpal; Shevkani, Khetan
    The effects of degree of milling (DOM) between 0 and 8% on physico-chemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars were studied. Ash, protein, lipids and minerals decreased while blue value and crystallinity increased with increase in DOM. The colour parameters (a? b?) and cooking time (CT) decreased while L?(lightness) increased with increase in DOM. Elongation ratio (ER), gruel solid loss (GSL), length/breadth (L/B) and paste viscosities during cooking increased with increase in DOM. Short grain rice contained lower ash, protein, lipids, Mn, K, Ca, CT and GSL than long grain while the later showed higher crystallinity, Mn, P, K, Ca and ER. Paste and dough characteristics measured using Rheometer and Mixolab, respectively correlated well and differed with cultivar and DOM. Short and long grain cultivars showed variation in loss of different chemical constituents during varied DOM causing variation in cooking characteristics. ? 2018 Elsevier Ltd
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    Composition, bioactive compounds and antioxidant activity of common Indian fruits and vegetables
    (Springer India, 2016) Singh,Jatinder Pal; Kaur, Amritpal; Shevkani, Khetan; Singh, Narpinder
    The present work was undertaken to evaluate the chemical composition (proximate, minerals and dietary fibre), colour parameters, antioxidant activity and polyphenol profiles of different fruits (pomegranate, kinnow, mango, banana, jambolan, grapes and sapodilla) and vegetables (beetroot, brinjal, orange carrot, bitter gourd, mentha and spinach). The amount of insoluble dietary fibre was higher than soluble dietary fibre for all fruits and vegetables. Vegetables showed superior mineral composition (higher amounts of K, Ca and Fe) as compared to fruits. Total phenolic content (TPC) and antioxidant activity (ABTS and DPPH) ranged from 354.9 to 1639.7?mg?GAE/100?g, 2.6 to 5.5 and 3.0 to 6.3?mM?TE/g, respectively for different fruits, while it ranged from 179.3 to 1028.6?mg?GAE/100?g, 2.1 to 4.7 and 2.0 to 5.0?mM?TE/g, respectively for different vegetables. Gallic acid, protocatechuic acid, catechin, caffeic acid, ferulic acid, sinapic acid, quercetin, resveratrol and kaempferol were detected and quantified in different fruits and vegetables. The results highlighted that fruit peels could be used as valuable sources of minerals and polyphenols having high antioxidant activity. ? 2016, Association of Food Scientists & Technologists (India).
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    Bioactive constituents in pulses and their health benefits
    (Springer India, 2017) Singh,Balwinder; Singh, Jatinder Pal; Shevkani, Khetan; Singh, Narpinder; Kaur, Amritpal
    Pulses are good sources of bioactive compounds such as polyphenols, phytosterols and non-digestible carbohydrates that play important physiological as well as metabolic roles. These compounds vary in concentration amongst different pulse species and varieties. Pulse seed coats are rich in water-insoluble fibres and polyphenols (having high antioxidant activities), while cotyledons contain higher soluble fibres, oligosaccharides, slowly digestible and resistant starch content. Ferulic acid is the most abundant phenolic acid present in pulses, while flavonol glycosides, anthocyanins and tannins are responsible for the seed coat colour. Sitosterol (most abundant), stigmasterol, and campesterol are the major phytosterols present in pulses. Pulse fibres, resistant starch and oligosaccharides function as probiotics and possess several other health benefits such as anti-inflammatory, anti-tumour, and reduce glucose as well as lipid levels. Beans and peas contain higher amounts of oligosaccharides than other pulses. Processing methods affect resistant starch, polyphenol composition and generally increase antioxidant activities of different pulses. In this review, the current information on pulse polyphenols, phytosterols, resistant starch, dietary fibre, oligosaccharides, antioxidant and associated health benefits are discussed. ? 2016, Association of Food Scientists & Technologists (India).
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    Structural, Morphological, Thermal, and Pasting Properties of Starches From Diverse Indian Potato Cultivars
    (Wiley-VCH Verlag, 2018) Singh, Narpinder; Kaur, Amritpal; Shevkani, Khetan; Ezekiel, Rajrathnam; Kaur, Prabhjot; Isono,Naoto; Noda, Takahiro
    Starches from 42 diverse Indian potato cultivars are evaluated for diversity in structural (amylose content and amylopectin chain length distribution), morphological (granules size distribution), thermal, and pasting properties. Amylose content varied between 6.5 and 32.2% while the proportion of short (DP 6?12), medium (DP 13?18), and long (DP 19?30) amylopectin chains varied in the range from 37.2 to 45.4%, 35.6 to 39.1%, and 17.8 to 24.5%, respectively. Starches with higher transition temperature showed lower enthalpy of gelatinization. The proportion of small granules (<10 ?m) correlated negatively to short amylopectin chains (DP 6?12), peak viscosity, and breakdown viscosity. Transition and pasting temperature related negatively to the proportion of short and medium chains of amylopectin (DP 6?12 and 13?18, respectively), while positively to that of long chains (DP 19?30). Peak viscosity and breakdown viscosity has a negative relation while the final and setback viscosity have a positive relation with long amylopectin chains. ? 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim