Physicochemical properties of acetylated starches from some Indian kidney bean (Phaseolus vulgaris L.) cultivars

Starches separated from four kidney bean cultivars were modified by acetylation to reduce retrogradation and increase gel stability and compared with respective native starches (data of native starch reported by Wani et al., 2010 ). Acetylation was carried out by treating starches with 0.04 and 0.08 g of acetic anhydride per gram of starch dry weight basis (dwb) at 25 °C and pH between 8.0 and 8.5. The extent of acetylation increased proportionally with the concentration of acetic anhydride used. The pasting curves of 10.7% starch determined by Rapid Visco Analyzer at 160 rpm showed that acetylation decreased the setback viscosity values by 0.64–34.58% and pasting temperature by 4.4–9.2 °C when compared with the native starch. Differential scanning calorimetry observations also revealed significant (P ≤ 0.05) decrease in gelatinisation temperature of acetylated starches than the corresponding native starches. Hardness of starch gels varied between 14.3 and 44.0 g, which was significantly (P ≤ 0.05) lower than the corresponding native starch gels.     

Studies on the morphological,thermal and rheological properties of starch separated from some Indian potato cultivars

The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Badshah, Kufri Jyoti, Kufri Sindhuri and S1) were investigated for morphological, thermal, rheological, turbidity and water-binding properties. The starch separated from all the five potato cultivars had a granule size ranging between 15–20 μm and 20–45 μm. The shape of starch granules varied from oval to irregular or cuboidal. Starch isolated from cv. Kufri Badshah had largest irregular or cubiodal granules while starch from cv. Kufri Chandermukhi had small and oval granules. The transition temperatures and enthalpy of gelatinization (ΔH_gel) were determined using differential scanning calorimetry (DSC). The enthalpy of retrogradation (ΔH_ret) of gelatinized starch was also determined after 14 days of storage at 4°C using DSC. Kufri Chandermukhi starch showed the lowest ΔH_gel and ΔH_ret while Kufri Badshah starch showed the highest values. ΔH_gel and ΔH_ret values of 12.55 J/g and 6.42J/g, respectively, for Kufri Chandermukhi starch against 13.85 J/g and 8.61 J/g, respectively, for Kufri Bhadshah starch were observed. Rheological properties of starches from different potato cultivars, measured using the Dynamic Rheometer during heating and cooling, also differed significantly. The starch from cv. Kufri Badshah showed the highest peak G′ and G″ and lowest tan δ. The starches having higher peak G′(G′ at gelatinization temperature) showed higher breakdown in G′ and vice versa. The turbidity of gelatinized aqueous starch suspensions from all potato cultivars increased with increase in storage period. Starches with low water binding capacity had higher G′ and G″ and lower tan δ values.     

Physicochemical,morphological, and thermal properties of starches separated from bulbs of four Chinese lily cultivars

The starches separated from bulbs of four different lily cultivars (Lanzhou, Pinglu, Yixing‐1, and Yixing‐2) were investigated for physicochemical, morphological, crystalline, and thermal properties. AM content of lily bulbs starches from different cultivars ranged from 19.46 to 25.17%. The swelling power of starches ranged between 14.4 and 21.3 g/g, and the solubility ranged from 8.92 and 16.6% at the temperature of 85°C. Four cultivars of lily starches paste had excellent transparency and the transmittance value of Lanzhou lily as high as 54.7%. The transmittance of the gelatinized aqueous starch suspensions, from all lily cultivars, decreased with increase in storage period. The shape of starch granules varied from triangular to cylindrical and XRD of four lily starches all showed B‐type pattern. The transition temperatures and enthalpy of gelatinization (ΔH_gel) were determined using DSC. T_p varied from 62.52 to 65.25°C. Pinglu lily starch showed the highest ΔH_gel and gelatinization range (T_c–T_o) index among starches from four different lily cultivars.     

Morphological,thermal and rheological properties of starches separated from rice cultivars grown in India

Morphological, thermal and rheological properties of starches separated from five rice cultivars (PR-106, PR-114, IR-8, PR-103 and PR-113), varying in amylose content, were studied. Amylose contents of starches separated from PR-103, IR-8, PR-106, PR-114 and PR-113 were 7.83, 15.62, 16.05, 16.13 and 18.86%, respectively. The granular size, measured using a Scanning Electron Microscope, varied from 2.4 to 5.4 μm in all rice starches. PR-103 starch, with lowest average granular size, amylose content and solubility, had the highest swelling power, while PR-113 starch, with the highest average granular size and amylose content had the lowest swelling power. PR-103 starch showed highest transition temperatures, enthalpies of gelatinization, peak height index, range and enthalpies of retrogradation. The retrogradation (%) was observed to be highest in PR-113 starch and lowest in PR-103 starch. The changes in rheological parameters of rice starches during heating were measured using a Dynamic rheometer. PR-113 rice starch showed the highest G′, G″ and breakdown in G′ values, whereas PR-103 starch showed the lowest values for these parameters. Turbidity value of gelatinized pastes from all rice starches progressively increased up to the 3rd day during refrigerated storage, PR-103 starch paste showed the lowest turbidity value and PR-113 starch showed the highest value. The syneresis (%) of starch pastes, from different rice cultivars during storage at 4 °C, was also measured. The syneresis of starch pastes from all rice cultivars, except PR-103, increased with storage. PR-103 starch paste showed negligible syneresis during storage.     

Physicochemical,morphological, structural,and thermal characteristics of starches separated from Bulbus fritillaria of different cultivars

The starches studied from the nine Fritillaria species had differently shaped and sized granules but all of them showed the presence of smooth, round, or elliptic‐shaped, indicating that the isolation process did not destroyed the starch granules. The nine Fritillaria starches presented different AM content, moisture content, ash content, particle size, swelling power, solubility, water absorption capacity and light transmittance. The starches isolated from Chuan‐Beimu species exhibited a higher amount of crude protein content and lower amount of AM than other the groups, which had lower swelling power, higher solubility and light transmittance. All the nine Fritillaria starches had an XRD pattern of the B‐type. In addition, F. hupehensis, F. walujewii and F. ussuriensis starches with fairly large‐sized or irregular granules had higher T_p and ΔH_gel values than that isolated from the four Chuan‐Beimu species. The results obtained yielded information about the possible behavior of these starches when being used in certain applications. Cluster analysis results showed that this classification method based on macromolecule chemical compounds (starch) is original and credible in the quality control of various Beimu. In addition, it provided more information to the authentication systematics taxonomy methods including morphological, histological and molecular biological techniques of Fritillaria species.     

Relationships between various physicochemical,thermal and rheological properties of starches separated from different potato cultivars

Various physicochemical, thermal and rheological properties of starches separated from Indian potato cultivars were related to each other using the Pearson correlation. Amylose content, water‐binding capacity (WBC), swelling power, solubility, ash content, transmittance, syneresis and consistency coefficient (K) were determined. Amylose content was significantly correlated with swelling power (r = 0.904), transmittance (r = 0.656) and syneresis (r = 0.777) of the starches. Thermal properties such as transition temperatures (T_o, T_p and T_c), gelatinisation range (R), gelatinisation enthalpy (ΔH_gel) and peak height index (PHI) of the starches were measured using differential scanning calorimetry (DSC). T_o, T_p and T_c were positively correlated with swelling power and negatively correlated with solubility and WBC. PHI was positively correlated with WBC and negatively correlated with ash content and swelling power. R had a negative correlation with WBC (r = ?0.726) and PHI (r = ?0.737). A positive correlation between R and T_c was observed. WBC was negatively correlated with swelling power (r = ?0.749). Syneresis of potato starches was positively correlated with transmittance, ash content, swelling power and amylose content. K was positively correlated with amylose content (r = 0.587). The results showed a significant variation in various functional and thermal properties of starches separated from different potato cultivars. Copyright © 2004 Society of Chemical Industry     

Effects of freezing preservation on mango (Mangifera indica,L.) peroxidase

This work describes the effects of freezing preservation on mango (cvs Lippens and Smith) peroxidase (E.C. 1.11.1.7); POD). Frozen mango slices showed lower levels of POD activity than raw fruits (17% cv Lippens; 50% cv Smith after 2 months storage time). A regeneration of this activity was found after 6 months of frozen storage. Regeneration continued to the end of the study (12 months) in both cultivars. During the whole period of storage, inactivation rates in Smith POD were higher than in Lippens. The isoenzymic pattern of Lippens POD showed four strongly anionic species that did not appear in the Smith pattern. The activity of these four bands is the most stable to low temperatures, and is the possible cause of the major resistence of Lippens peroxidase to freezing and frozen storage. Thus the Smith cultivar may be more suitable for freezing preservation.     

Characterisation of green aroma of raw mango (Mangifera indica L.)

The latex of two varieties of mango, Alphonso and Batali, was collected during the de-stalking of freshly picked matured unripe (raw) fruit. The essential oil of each of the mango latices was isolated by high vacuum distillation at ambient temperature. The major component of each essential oil possessing the characteristic aroma of green mango, was isolated by preparative gas-liquid chromatography and was characterised as cis-ocimene and β-myrcene, respectively.     

Physicochemical,thermal, rheological,and morphological properties of flour from different guar seed (Cyamopsis tetragonoloba) cultivars

In the present study, physicochemical, thermal, rheological, and morphological properties of flours from guar seed cultivars (G80, Ageta 112, and HG365) were assessed. Ageta 112 flours showed the highest protein content (26.78%) and varied significantly from G80 and HG365. The fiber, ash, and carbohydrate displayed significant differences in all three guar cultivars. Maximum gum content was extracted from G80 (41.19%), followed by HG365 and Ageta 112. Assessment of thermal properties revealed G80 flours with highest onset, peak, and endset temperature. Flours from cultivar Ageta 112 were recorded with highest paste temperature and peak viscosity and G80 flours showed lowest setback viscosities. Scanning electron microscopy was used to observe the morphological structure of different guar seed flour. Scanning electron micrographs presented the internal structure containing the galactomannans. Several significant correlations between physicochemical, gum yield, and thermal properties were revealed by Pearson correlation.     

Studies on the physicochemical,morphological, thermal and crystalline properties of starches separated from different Dioscorea opposita cultivars

The physicochemical, morphological, thermal and crystal properties of the starches separated from four different Dioscorea opposita Thunb. cultivars (Taigu, Ribenbai, Wenxi and Zhongbowen) were studied. Amylose contents of D. opposita Thunb. starches from different cultivars ranged from 21.17% to 25.00%. The shape of starch granules separated from different D. opposita Thunb. cultivars varied from round or oval to elliptic or caky. The surface of the starch granules appeared to be smooth without any fissures. The average particle diameter of starches from different D. opposita Thunb. cultivars ranged from 25.90 to 28.06 μm. The transition temperatures (T_o, T_p and T_c) and enthalpy of gelatinization (ΔH_gel) were determined using differential scanning calorimetry (DSC). T_o, T_p, T_c and ΔH_gel of D. opposita Thunb. starches ranged from 73.1 to 73.9, 77.6 to 80.4, 82.1 to 85.9 °C and 6.548 to 12.13 J/g, respectively. The crystal type of starches separated from different D. opposita Thunb. cultivars was a typical C-type pattern. The relative degree of crystallinity of the four D. opposita Thunb. cultivars starches were about 38.79%, 39.88%, 41.67% and 49.03%, respectively.     

Pectic polysaccharides during ripening of mango (Mangifera indica L)

The content of pectin decreased from 2.0 to 0.7% fresh weight (FW) and there was a concomitant increase in free galacturonic acid from 36 to 168 mg% FW during ripening of mango. Ion exchange chromatography on DEAE/cellulose resolved the pectic fraction into seven distinct peaks, with all of them showing a drastic decrease in pectin content and molecular weight as fruit ripening progressed, which indicated significant depolymerisation in vivo. Fraction I appeared to be an arabinogalactan‐type polymer, while fractions II and III were heterogalacturonans containing more than 60% galacturonic acid. Hydrolases implicated in pectin depolymerisation were polygalacturonase (PG), pectin methyl esterase (PME), galactanase, arabinanase and β ‐galactosidase. They all showed a climacteric peak in activity during ripening, except for PME which showed a continuous decrease in activity after an initial increase. These results are discussed in the light of fruit softening during ripening. Copyright © 2003 Society of Chemical Industry     

Physicochemical and structural properties of starches isolated from corn cultivars grown in Indian temperate climate

Starches isolated from five corn cultivars namely C4, C5, C6, C8, and C15 were investigated for their physicochemical and structural properties. The amylose content of corn starches varied from 24.74 to 30.32 g/100 g among the cultivars. The starch granules showed polyhedral granule shapes and differences in their mean granule size ranged from 2.3 to 19.5 μm. The starch samples showed A-type diffraction pattern with strong reflection at 15.25, 18.11, and 23.33°. Pasting profile, textural, and thermal properties of corn starch showed the cultivar differences. Raman spectroscopy showed the major band intensities at 1340, 1082, 940, 865, 523, 485, 440, and 412 cm^?1. Syneresis and turbidity of gelatinized pastes of starches varied among the cultivars and increased progressively with the increase in storage period. The present study can be used for identifying differences between corn genotypes for starch quality and could provide guidance to possible industries for their end use.     

Relationship of aroma and flavour characteristics of mango (Mangifera indica L.) to fatty acid composition

Glyceride content and fatty acid composition of pulp from five commercial varieties of table-ripe mangoes having wide differences in aroma and flavour were studied. In addition, the Alphonso mango was examined at various stages of ripening at two different temperatures. Although the same type of fatty acids were present in all varieties of ripe mango there were differences in quantitative distribution. During the ripening of Alphonso mango at ambient temperature (25 to 30 °C), there was an increase in the glyceride content of the pulp, followed by rapid changes in fatty acid composition and in aroma and flavour, while at low temperature (10 ± 2 °C), where ripening was considerably delayed, there were no appreciable changes in glyceride content and in fatty acid composition of the pulp or in aroma and flavour. A correlation was ascertained between organoleptically evaluated aroma and flavour characteristics of mango pulp and the ratio of palmitic acid to palmitoleic acid.     

Physicochemical properties of starches obtained from Polish potato cultivars

Selected physicochemical, thermal, and rheological properties of starches isolated from new Polish potato varieties were determined. The starches contained 25.7–30.0 g/100 g d.m. of amylose and 59.5–90.2 mg/100 g d.m. of phosphorus. Gelatinization temperatures were 62.6–64.0, 68.9–69.9, and 73.6–77.0°C for T_O, T_P, and T_E, respectively, whilst enthalpy of gelatinization amounted to 11.1–15.3 J/g. The retrogradation degree of starch was from 52.90 to 78.53%. Pasting curves showed significant differences between the starches. Peak viscosity and final viscosity ranges were 2035–4458 and 1931–2985 mPa · s, respectively. Starch pastes exhibited non‐Newtonian, shear thinning, and thixotropic behavior. After cooling they demonstrated diversified viscoelastic properties, however, all of them were classified as weak gels. Significant linear correlations among selected rheological parameters and amylose and phosphorus content were found. Results of principal component analysis demonstrated an ability to differentiate the starches isolated from different potato varieties.     

Phytochemical composition,cellular antioxidant capacity and antiproliferative activity in mango (Mangifera indica L.) pulp and peel

Cellular antioxidant activity (CAA) and inhibition of hepato‐cellular carcinoma (HepG2) proliferation were evaluated for the first time in the pulp and peel of mango cultivars. Comparatively, peel had high flavonoids and tocopherols content and showed significant antioxidant activity. Among all the studied cultivars, the Xiao Tainong peel was predominant with highest fistein, mangiferin and alpha‐tocopherol content and significant cellular antioxidant activity value 2986 ± 380 μmol QE/100 g FW. The HepG2 cells antiproliferation was maximum in the peel of Da Tainong and pulp of Aozhou with lowest EC₅₀ values, 2.35 ± 0.65 (peel) and 185.4 ± 10.9 (pulp) mg mL^?1, in a dose‐dependent manner. Negative associations of flavonoids and tocopherol compounds with CAA and antiproliferative activity in mango confirmed synergistic, additive or antagonistic actions of phytochemicals. The current study suggests that mango peel could be used as a value added ingredient or functional food and may contribute considerably to promote consumer health.