Balmeet Singh Gill

Morphological, thermal and rheological properties of starches from different botanical sources

Corn, rice, wheat and potato are the main sources of starches which differ significantly in composition, morphology, thermal, rheological and retrogradation properties. Cereal starches contain a significant quantity of phospholipids, while potato starch is rich in esterified phosphorus. Potato starch exhibits higher swelling power, solubility, paste clarity and viscosity than wheat, rice or corn starches. Morphological characteristics, such as shape and size of the starch granules, exhibit significant differences. Potato starch granules are smooth–surfaced, oval and irregular or cuboidal-shaped while corn, rice and wheat starch granules are angular, pentagonal and angular; and spherical and lenticular–shaped, respectively. Corn, rice and wheat starch granules are less smooth–surfaced than potato starch granules. Potato starch granules are largest (<110 μm) in size followed by wheat (<30 μm), corn (<25 μm) and rice (<20μm) starches. Gelatinization temperatures (To, Tp, Tc) and enthalpies of gelatinization (ΔHgel) of starches from different sources also differ significantly. Corn and rice starches generally show higher transition temperatures than wheat and potato starches while the ΔHgel values are higher for potato and wheat starches. Potato starch shows a higher tendency towards retrogradation than the cereal starches. The rheological properties, such as storage modulus (G′) and loss modulus (G″) of the starches from the different sources increase to a maximum and then drop during heating of all the starches. Potato starch shows highest peak G′, G″ and lower tan δ than corn, rice and wheat starches during the heating cycle.

Physicochemical, morphological and pasting properties of acid treated starches from different botanical sources

Effect of acid modification on physico-chemical, morphological and pasting properties of banana, sweet potato, lotus stem and wheat starches were studied. Results revealed that swelling power, solubility and water binding capacity of all starches decreased by acid modification. By acid modification starch granules from different varieties tended to appear fused and less smooth than the native starch granules. The pasting properties of native starches of all different varieties have significantly decreased following acid modification. Acid modified starches showed higher syneresis as compared to native starches.

Physicochemical Changes in Seven Tomato (Lycopersicon esculentum) Cultivars During Ripening

Seven tomato cultivars were studied for compositional changes during ripening at green, breaker, turner, and ripe stages. Result indicated changes in total soluble solids (4.15 to 6.62 g/100 g), acidity (0.36 to 0.54 g/100 g), reducing sugars (0.76 to 4.04 g/100 g), total sugars (1.67 to 5.52 g/100 g), lycopene in skin (0.07 to 14.28 mg/100 g), and in pulp (0.04 to 6.73 mg/100 g) during ripening from green to red ripe stage. Cultivar UC-828 was found superior with respect to total soluble solids (6.62 g/100 g), reducing sugars (4.04 g/100 g), and total sugars (5.52 g/100 g) where as cultivar 8–2–1–2–5 was found superior with respect to lycopene in skin (14.28 mg/100 g) and in pulp (6.73 mg/100 g). Hunter color values showed a change from negative value of ‘a’ (greenness) to positive values (redness) where as ‘b’ decreased. The (b/a) and tan−1 (b/a) showed a similar pattern of first increased and then decreased. The puncture resistance was decreased from 10.5 to 2.3 N indicating softening during ripening. Correlation studies showed that lycopene content best correlated with Hunter ‘a’ values during ripening (R2 = 0.84 to 0.93). Intercultivar variation in physicochemical parameters at all stages of ripening revealed that Castle Rock was the best cultivar.

Production and Characterization of Microbial Carotenoids as an Alternative to Synthetic Colors: a Review

Carotenoids are important group of pigments with specific applications in food, pharmaceutical, and cosmetic industries owing to their biological properties like antioxidant, anti-carcinogenic, and immune-modulator. The demand of carotenoids as nutraceutical compounds has triggered the research to explore a commercially viable process for economic production of carotenoids. This article presents a review of carotenoids from microbial origin identifying the conditions used for their cultivation and applications.

The Impact of Starch Properties on Noodle Making Properties of Indian Wheat Flours

Abstract The physico-chemical and noodles making properties of flour milled from three bread (PBW-154, PBW-343, and PBW-373) and one durum (PDW-233) wheat cultivars were studied. Noodles were evaluated for cooking and textural properties. The starches were also separated from these cultivars and investigated for morphological, thermal, rheological, and retrogradation properties. Protein, ash, SDS sediment value, and swelling power of flour milled from different varieties varied between 10.0–10.9%, 0.53–0.71%, 19.5–33.5 mL, and 7.4–9.8 g g−1, respectively. Falling number values of flours indicate that the flour had been milled from sound wheat. PDW-233 grains showed highest fracture force while flour from PBW-154 cultivar showed highest SDS value (33.5 mL). The noodles prepared from PBW-154 flour showed lowest cooked weight, highest oil absorption, and highest amylose content. The amylose content of starches separated from different wheat cultivar varied between 20.5 and 29.2%. The starches from all the wheat cultivars had a granule size ranging between 8 and 25 µm and granules shape varied from oval to spherical. PBW-373 starch had largest average granule size while PBW-343 starch showed the smallest average granule size. The transition temperatures, enthalpy of gelatinization (ΔH gel), enthalpy of retrogradation (ΔH ret), peak height index (PHI) and range were determined using differential scanning calorimetry (DSC). PBW-343 starch showed highest onset temperature, peak temperature, and conclusion temperature of 61.4, 65.3, and 70.1°C whereas PDW-233 starch showed the least values of 58, 62.1, and 67.6°C, respectively. The ΔH ret of gelatinized starch from all wheat cultivars was determined after 2 weeks of storage at 4°C. PBW-373 starch showed the highest ΔH gel and ΔH ret while PBW-343 showed lowest values for the same. The retrogradation (%) was observed to be highest in PDW-233 starch and lowest in PBW-343 starch. The synersis (%) was observed to be highest for PBW-343 starch, which increased during storage of starch pastes from all the varieties. The swelling power of flour was observed to be associated with noodle textural properties. The flour showing lower swelling power and small starch granules resulted into noodles having higher hardness, chewiness, cohesiveness, and packability.

Effect of incorporating hydrothermal, kilned and defatted oats on antioxidant and chapatti making properties of wheat flour.

Oats were subjected to treatments like defatting, hydrothermal cooking and kilning, milled into flour and then the control and treated flours were incorporated into wheat flour at 25% and 50% levels and chapatti making behaviour and antioxidant properties were studied. The treatments significantly affected the antioxidant properties of oats. Incorporating oat flours to wheat increased total phenolic content but lowered the antioxidant activity however both were decreased significantly upon baking. The reducing power of the oat blended flour was higher than the wheat flours and ranged from 8.0 to 15.5 μmol AAE/g and was further increased upon baking. The metal chelating activity of flour blends varied from 62.0% to 73.8% and further increased upon baking. After baking the total flavonoid content was lowered and ranged from 308 to 389 μg CE/g. The non-enzymatic browning index significantly increased up to 27.6% upon baking.

Gelatinization and X-ray Crystallography of Buckwheat Starch: Effect of Microwave and Annealing Treatments

Buckwheat, a non-glutinous pseudo-cereal having a long and traditional history as a food source in Asia, Europe, and the United States, has many beneficial health aspects. However it has suffered from declining production during the past few years. In order to prevent further decline of buckwheat production new products need to be developed for the consumer market and more research need to be carried to study the effect of different processing parameters on buckwheat characteristics. This study was carried out to investigate the effect of microwave heat-moisture and annealing processes on buckwheat starch that had been dried to three moisture levels: 30.3, 40.0, and 50.4 kg/100kg. Starch samples were analyzed using a differential scanning calorimeter, a colorimetric amylose leaching tests, and an x-ray diffractometer. Additional moisture levels in the starch treatment groups (15.2% and 25.8%) were produced for the x-ray diffraction tests. DSC data indicated that moisture levels had a significant effect on onset melting temperature, peak melting temperature and enthalpy of fusion. In addition, heat treatment and interaction of moisture with heat treatment both had a significant effect on amylose leaching results. Significant effect on starch was found mainly at the 50.4 kg/100 kg moisture level as compare to the 30.3 and 40.0 kg/100 kg moisture level. X-ray diffraction readings showed a stable D-space placement for all treatment groups. Intensity visibly increased with decreased moisture level and with heat treatment in case of 40.0% and 50.4% moisture level starches. Resistance to amylose leaching and melting at higher temperatures for higher moisture level buckwheat starch samples was attributed to increased networking among the amylose and amylopectin components in the buckwheat starch.

Mineral and amino acid contents of different flaxseed cultivars in relation to its selected functional properties

This study was conducted to determine selected functional properties of six flaxseed cultivars in relation to its nutritional value to aim at selection of a cultivar that would be more nutritive and contribute to desirable functional properties. The determination of macro-elements and trace elements was carried out by atomic absorption spectrophotometry whereas amino acid analyzer was used to determine the amino acid contents. Various flaxseed cultivars showed significant (P < 0.05) differences in their protein, fat and fibre contents. Flaxseed flours exhibited good gelling, water binding, foaming and emulsifying properties. The tendency of value of macrominerals was: Mg > K > Na whereas for micro elements the trend was: Zn > Mn > Cu > Fe. Flaxseed proteins were of high nutritional value on account of their essential amino acid (EAA) content. Six EAA were present with tryphtophan, valine and lysine being the predominant amino acids. The EAA and non-EAA represented 21.06–50.65 and 49.35–78.94 %, respectively of total amino acids. Most of samples had high acidic to basic amino acid ratio. Pearson correlations showed significant dependence of functional properties on nutrient composition. “LC-2023” cv. was the most potential cultivar as it varied significantly from other cultivars in its mineral and amino acid contents.

Rheological and structural properties of starches from different Indian wheat cultivars and their relationships

ABSTRACT The structural, pasting, and dynamic rheological properties of starches isolated from six Indian wheat (Triticum aestivum L.) cultivars were evaluated. The amylose content of starches ranged between 18.35–20.58%; subsequently, these were normal-type starches. The light transmittance of gelatinized starch pastes decreased with increase in storage periods at 4°C. Scanning electron micrographs revealed bimodal size distribution of starch granules, with smaller B- and larger A-type. X-ray diffraction (XRD) pattern revealed typical A-type crystalline starch, with the highest crystalline index (CI) for cv.C-306. Fourier transform infrared (FTIR) spectroscopy was performed to understand the chemical bonding and short-range molecular order of starches. The highest 1047/1022 absorbance ratio (0.8666) for cv.C-306 justified its more crystalline nature. Peak viscosity (PV), trough viscosity (TV), and final viscosity (FV) were the highest for cv.WH-147 starch (1602, 1542, and 2123 cP, respectively). Peak G’, peak G”, and breakdown in G’ during heating were in the range of 5052–9067, 563–1463, and 909–3567 Pa, respectively. The power law model agreed well with the steady shear properties of starch pastes. Non-Newtonian fluid behaviour of starch was observed with n value ranging between 0.22 and 0.32. PV, FV, TV, and setback viscosity (SV) were significantly correlated to each other. Peak G’ exhibited negative correlation with TG’ (temperature at peak G’), light transmittance after 96 and 120h storage periods, and positively correlated with breakdown in G’. A significant positive correlation was observed between peak G” and tanδ during heating. Complex viscosity (η*) was also found positively correlated to G’.

Indian wheat (Triticum aestivum L.) cultivars: physical characteristics, micronutrients and heavy metal content

Six (C-306, PBW-373, WH-147, WH-1025, PBW-343 and PBW-502) Indian wheat cultivars were evaluated for their physical, milling and colour characteristics. The micronutrients and heavy metals were detected using an atomic absorption spectrophotometer. The physical parameters of grains revealed that WH-1025 had the smallest whereas WH-147 had the biggest grain size. Cultivar’s C-306 and WH-147 showed significantly (P≤0.05) higher (58.828 and 58.805%, respectively) grain sphericity, so grains from these cultivars were more spherical in shape compared to other cultivars under study. The grains of studied cultivars were mealy and intermediate vitreous as reflected from their bulk and true density values. Cultivar WH-147 was the heaviest (4.313 g/100 grains) and also showed more volume (3.9 ml/100 grains) as compared to others, which reflected its importance for higher flour yield. Grains from cultivar WH-147 also showed the highest hunter L* and b* values, whereas grains from C-306 had the lowest hunter L*, a* a...