Extrusion assisted interaction of rice starch with rice protein and fibre: Effect on physicochemical, thermal and in-vitro digestibility characteristics.

Rice starch has high digestibility due to its large carbohydrate content. Macromolecular enrichment of starch has the tendency to retard rate of starch hydrolysis. Hence, the current investigation was aimed to check the combined effect of extrusion assisted addition of rice protein (0, 10, 15 and 20 %) and fibre (0, 4, 8 and 12 %) to rice starch on physico-chemical and in-vitro digestibility characteristics of starch extrudates. It was observed from the study that 'a' and 'b' values, pasting temperature and resistant starch of starch blends and extrudates increased with the addition of protein and fibre. However, lightness value, swelling index, pasting properties and relative crystallinity of blends and extrudates decreased with the addition of protein and fibre. Maximum increase in thermal transition temperatures was observed for ESP3F3 extrudates due to absorption capacity of protein molecules which led to late onset of gelatinization. Therefore, enrichment of protein and fibre to rice starch during extrusion can be considered as a novel approach to reduce rate of rice starch digestion for catering nutritional requirements of diabetic population.

Effect of Gamma-irradiation on the Physicochemical, Functional, and Antioxidant Properties of Unpigmented Brown Whole Rice Flour.

Whole grain brown rice, being a rich source of fiber and other bioactive compounds like polyphenols is effective in reducing the risk of chronic diseases including cardiovascular diseases, hypercholesterolemia and Type II diabetes. The study was aimed to evaluate the effect of gamma irradiation on the physicochemical, functional and antioxidant properties of whole grain brown rice flour. The brown rice flour was conditioned to two different moisture contents of 10% and 12% and treated with gamma irradiation doses of 0 kGy (native or control), 2.5 kGy and 5 kGy. Moisture, protein, fat, ash and carbohydrate content of native flour was found as 10 g/100 g, 6.54 g/100 g, 1.54 g/100 g, 1.0 g/100 g, and 81.48 g/100 g, respectively. The hunter color 'L', 'a', and 'b' values of the native brown rice flour sample were found as 81.95, -0.97 and 17.36, respectively and were non-significantly (p ≥ 0.05) affected by gamma irradiation. Apparent amylose content was observed to decrease significantly (p ≤ 0.05) from 29.97 to 20.30 g/100 g with the increase in gamma irradiation dose and moisture content. The pasting properties such as peak viscosity, trough viscosity and final viscosity of all the flour samples decreased significantly (p ≤ 0.05) with the increase in irradiation dose. The functional properties such as water and oil absorption and emulsion capacities were increased while emulsion stability and foaming stability decreased upon irradiation. Irradiation led to an overall increase in the antioxidant activity of rice flours. In general, FTIR spectra revealed a decrease in the absorption intensities of the functional groups. Therefore, it can be concluded that gamma irradiation can be used as a tool to modify the physicochemical properties of rice flours as well as to improve their antioxidant properties.

Upscaling of Apple By-Product by Utilising Apple Seed Protein as a Novel Wall Material for Encapsulation of Chlorogenic Acid as Model Bioactive Compound.

Encapsulation is a versatile technique used to protect sensitive bioactive compounds under gastrointestinal conditions. In this study, nanoencapsulation of chlorogenic acid into the apple seed protein matrix was performed using the green technique ultrasonication to protect it from harsh gastric conditions and increase its biological activity and bioavailability upon digestion. Both nano (Nano-Chl) and native capsules (NT-Chl) were characterised by particle size, charge, structure, and morphology. The encapsulation efficiency, release behaviour, antioxidant and antidiabetic properties were also evaluated. The experimental results show that the particle size of the NT-Chl and Nano-Chl was found in the range of 1.4 µm to 708 nm. The encapsulation efficiency was found to be 69% and 80% for NT-Chl and Nano-Chl, respectively. Furthermore, an in vitro digestion study revealed that Nano-Chl showed controlled-release behaviour under simulated intestinal conditions in comparison to NT-Chl. Moreover, Nano-Chl showed enhanced antioxidant and antidiabetic activity in comparison to NT-Chl after simulated digestion. It was concluded that the protein from apple seeds could be utilised as a functional ingredient itself or as a wall material for the encapsulation of sensitive bioactive compounds. Furthermore, these encapsulated particles can be fortified into different food formulations for the development of functional food.

In-vitro digestibility of rice starch and factors regulating its digestion process: A review.

Rice is consumed as staple food by more than half of the world's population. However, it has high glycemic index because of high starch content and is associated with the development of diabetes. Therefore, it is important to devise strategies that could lower the digestibility of rice starch. Keeping this fact into consideration, the present study includes a review of factors that are known to regulate in-vitro digestibility of rice starch. This review also includes an overview of some previous and current in-vitro starch digestion methods along with their advantages and limitations. Regarding factors regulating in-vitro digestibility, physical encapsulation of starch within cell wall/macro-capsule, protein or dietary fibres retard rate of starch digestion. Also, interaction of polyphenols with rice starch results in formation of V-type inclusion complexes, resistant to digestion. This review provides sufficient information that can help food industries to develop suitable strategies for mitigating digestibility of rice starch.

Development of functional cakes rich in bioactive compounds extracted from saffron and tomatoes.

Demand for health-promoting food products rich in bioactive compounds and fibers is increasing. The current study was aimed to evaluate the physicochemical, antioxidant and sensory characteristics of whole wheat flour cakes enriched with tomato powder (TP), crude lycopene (CL) and saffron extracts (SE). Physical characteristics such as loaf weight of cakes containing TP increased significantly (p < 0.05) while loaf volume decreased as compared to the control. The color of the crust and crumb of cakes enriched with TP and CL was dark red while cakes containing SE were bright and yellowish. Firmness of the fresh cake samples was found in the range of 7.25-14.53 N. Antioxidant properties were significantly (p < 0.05) improved after enrichment of cakes with TP, CL and SE. The storage period increased the water activity while antioxidant activity and concentration of total carotenoids was reduced. Thus, cakes enriched with TP, CL and SE could be successfully developed with improved antioxidant properties, without compromising the sensory quality of the product. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05267-2.

Pasting, rheology, antioxidant and texture profile of gluten free cookies with added seed gum hydrocolloids.

The study was carried out with the aim of developing gluten free cookies using rice-chickpea composite flour. Guar and locust bean gum were added to formulations at two test concentrations (0.5 and 1.0%). To study the impact of these hydrocolloids, pasting and rheometry of dough formulations was carried out. The cookies produced were subjected to colour, spread ratio, hardness and antioxidant analysis. Protein (7.56 g/100g), fat (1.78 g/100g), ash (1.25 g/100g) and carbohydrate (80.41 g/100g) content of composite flour varied significantly (p ≤ 0.05) from both rice and chickpea. Higher viscosity, viscoelasticity and antioxidant profile was shown by dough formulations with added gums. Control cookies prepared without gums showed the L*, a* and b* values of 54.62, 3.81 and 35.97, respectively. With the addition of guar and locust bean gum, colour of the cookies became lighter. Spread ratio and hardness of cookies with added gums was higher.

Resistant starch from five Himalayan rice cultivars and Horse chestnut: Extraction method optimization and characterization.

In this study resistant starch (RS) was extracted from five Himalayan rice cultivars and Indian Horse chestnut (HCN) using porcine pancreatin enzyme following which it was subsequently characterized for its physicochemical, structural and functional properties. In vitro digestibility test showed that RS content of the rice cultivars and HCN was in the range of 85.5 to 99.5%. The RS extracted from the rice cultivars and HCN showed significant difference in the apparent amylose content (AAC), ranging between 31.83 to 40.68% for rice and 45.79% for HCN. Water absorption capacity (WAC), swelling and solubility index of RS ranged from 112-133.9%, 5.28-7.25 g/g and 0.033-0.044 g/g, respectively. The rice RS granules were polyhedral and irregular shaped with granular length in the range of 4.8-5.9 µm. The HCN RS granule morphology showed smooth surfaced, round, elliptical, irregular and oval shapes with average granular length of 21 µm. Pasting behavior also varied significantly between rice RS and HCN RS with later showing the lower values of pasting properties. Thermal properties (T0, Tp, Tc) and ΔH gel also varied considerably between the rice RS and HCN RS, wherein the highest values for peak gelatinization temperature and gelatinization enthalpy were seen for CH-1039. X-ray diffraction pattern of rice RS and HCN RS showed the characteristic A type of pattern in consonance with cereal starches.

Tomato powder and crude lycopene as a source of natural antioxidants in whole wheat flour cookies.

The nutritional quality of bakery products keeps on degrading from the process of baking, packaging, transportation and storage. The present study was carried out to evaluate the effect of addition of tomato powder (2 & 4/100 g of flour) and crude lycopene (50 & 100 mg/100 g of flour), which have potent antioxidant activity, on the nutritional quality and shelf life of cookies prepared from whole wheat flour. Color values i.e., a* and b* of freshly prepared cookies containing tomato powder (TP) were found in the range of 5.40-6.21 and 33.20-33.40 respectively, and that of crude lycopene (CL) in the range of 5.18-5.24 and 32.50-34.90 respectively, higher than the control (4.53 and 32.50, respectively). Significant (p < 0.05) and non-significant (p > 0.05) increase was observed in the total phenolic content of dough containing TP (0.54-0.72 mg GAE/g) and CL (0.46-0.59 mg GAE/g), when compared to control (0.38 mg GAE/g). Antioxidant properties like, DPPH scavenging activity, reducing power and inhibition of lipid peroxidation (ILP), and total carotenoid content (TCC) of dough and cookies increased significantly (p < 0.05) upon incorporation of TP and CL. Sensory properties of enriched cookies were comparable with that of control. Color values (a* and b*), hardness, TCC, ILP and TPC were reduced significantly (p < 0.05) with storage.

Sources, structure, properties and health benefits of plant gums: A review.

This article has been developed with the aim of reviewing the different sources, structure, extraction, composition, properties and health benefits of plant gums. Gums are known for their multifarious uses in food industries like bakery, meat, fruit and vegetable. Those obtained from different sources exhibit differences in their chemistry. All have a rich nutritional profile and require different methods for extraction/purification. Most studies reveal fair flow characteristics of plant gums. The X-ray diffraction studies and scanning electron micrographs confer their amorphous nature. General appearance of plant gums varies from yellow-cream to whitish in color. Water absorption and swelling are two essential physicochemical properties of the plant gums owing to their hydrophilic nature. In spite of hydrophilicity, plant gums exhibit significant interfacial properties like emulsifying and foaming. Aqueous plant gum dispersions are acidic in nature and show great variations in their rheological behaviour. Thermal properties (DSC) of the plant gums reveal endothermic as well as exothermic transitions. Many gums obtained from botanical sources have proven health promoting benefits.

Physico-chemical and rheological properties of Bengal gram (Cicer arietinum L.) starch as affected by high temperature short time extrusion.

Starch isolated from Desi Bengal gram seeds after conditioning to moisture contents of 16% and 18% was given a high temperature short time extrusion treatment (HTST). Physicochemical, morphological and rheological properties of untreated and treated starches were studied. Proximate composition of native starch revealed 9.2 g/100 g moisture, 0.01 g/100 g fat, 0.22 g/100 g ash and 0.25 g/100 g protein. Extrusion treatment led to a significant reduction (p ≤ 0.05) in amylose content of treatments from 32.5 to 30.4 g/100 g. Also there was reduction in Hunter colour 'L' value (91.6-78.5) with increase in 'a' (0.0-0.4) and 'b' (10.8-14.8) colour values of samples upon extrusion. Swelling index, solubility index and light transmittance presented a significant (p ≤ 0.05) increase upon extrusion. Pasting properties of extruded treatments decreased significantly(p ≤ 0.05) upon extrusion with increase in the moisture content from 16 to 18%. Scanning electron micrographs of native Bengal gram starch revealed small, spherical and smooth surfaced granules while granules were not visible after extrusion due to loss of granular structure. The storage modulus (G') of both untreated as well as treated starches increased with the increase in angular frequency, thereby depicting the dominance of elastic behaviour over viscous behaviour. The FTIR spectra of extruded samples revealed reduction in intensities of hydroxyl, alkyl and carbonyl stretches after extrusion.

Effect of extrusion on the physicochemical and antioxidant properties of value added snacks from whole wheat (Triticum aestivum L.) flour.

Nutritional quality of snacks prepared from cereals can be improved by the addition of crude lycopene (CL), tomato powder (TP) and saffron extracts (SE) which are known for their high photochemical content. The study was undertaken to prepare extruded snacks from whole wheat flour enriched with CL, TP and SE. Effect of extrusion on physicochemical, antioxidant and sensory properties of snacks was also investigated. Hardness of snacks containing CL and TP was higher than the control. Pasting properties of the formulations were significantly (p < 0.05) reduced upon addition of CL and TP. Total phenolic content (TPC) of the formulations with added TP increased significantly (p < 0.05). Antioxidant properties of snacks enhanced after enrichment. Extrusion significantly (p < 0.05) reduced the TPC, DPPH scavenging activity and pasting properties of snacks while, reducing power and inhibition of lipid peroxidation increased. Storage period lowered the hardness and antioxidant properties of snacks.

Effect of sonication and γ-irradiation on the properties of pea (Pisum sativum) and vetch (Vicia villosa) starches: A comparative study.

In present study, the physicochemical, functional and pasting properties of starch obtained from commercially used pea were compared with vetch, an underutilized pulse variety. Starch from each cultivar was subjected to sonication (33kHz for 45min) and a dual treatment in which sonication was followed by irradiation (5kGy). Apparent amylose content of the starch from two varieties varied significantly (p>0.05) from 31.08-27.58g/100g. Sonication and dual treatment decreased the amylose content of starches. Syneresis varied more or less insignificantly (p<0.05) upon sonication. However, upon dual treatment, syneresis decreased significantly (p>0.05) from 47.82-35.22g/100g (pea) and 46.36-26.98g/100g (vetch) during the storage period of 120h. A combined effect of sonication and irradiation treatment significantly (p>0.05) changed the functional properties and pasting characteristics of starches. The samples that received the sonication treatment alone varied non-significantly from native pea and vetch starch in their physicochemical, functional and pasting properties.

Effect of guar gum conjugation on functional, antioxidant and antimicrobial activity of egg white lysozyme.

This study was undertaken to analyze the effect of conjugation of egg-white lysozyme with guar gum. Lysozyme is an antimicrobial polypeptide that can be used for food preservation. Its antibacterial activity is limited to gram positive bacteria. Conjugation with polysaccharides like guar gum may broaden its activity against gram negatives. Conjugate was developed through Maillard reaction. Assays carried out included sugar estimation, SDS-PAGE, GPC, color, FT-IR, DSC, thermal stability, solubility, emulsifying, foaming and antioxidant activity. In addition, antimicrobial activity of the conjugate was determined against two gram positive (Staphyllococcus aureus and Enterococcus) and two gram negative pathogens (E. coli and Salmonella). Results showed higher functional properties of lysozyme-guar gum conjugate. The antioxidant properties increased from 2.02-35.80% (Inhibition of DPPH) and 1.65-4.93AAE/g (reducing power) upon guar gum conjugation. Conjugate significantly inhibited gram negative bacteria and the antibacterial activity also increased significantly against gram positive pathogens.

Effect of gamma irradiation on the physicochemical and structural properties of plant seed gums.

The objective of the study was to evaluate the effect of irradiation (0-5 kGy) on the physicochemical properties of two seed gums (guar and locust bean gum). The Hunter color parameters changed upon irradiation, namely "L" value decreased, whereas "a" and "b" values, i.e. redness and yellowness, increased. Irradiation reduced the final viscosity of gums at neutral and acidic pH. Increase in irradiation dose (0-5 kGy) increased the water absorption in the range of 11.75-14.61g/g and 20.04-23.99g/g in guar gum and locust bean gum, respectively. Rheological study of the gums revealed their gel behaviour with higher values of G' than G". G' in native guar gum was observed to increase in the range of 880.39-1332.29Pa while G" increased in the range of 194.21-239.77Pa as the test frequency was raised from 14.6-100s-1. In native locust bean gum, the G' and G" varied in the range of 476.50-1230.50Pa and 300.65-380.30Pa, respectively, under the applied frequency sweep. FT-IR revealed the presence of CH, COOH and CO groups in the guar as well as locust bean gum, in addition to the uronic acid and pyranose rings. The absorption of the functional groups declined upon irradiation.

Physico-chemical, rheological and antioxidant properties of sweet chestnut (Castanea sativa Mill.) as affected by pan and microwave roasting.

Sweet chestnut (Castanea sativa Mill.) belongs to the family Fagaceae and sub family Castaneoideae. Bioactive components such as tannins are present in sweet chestnut in high proportion giving astringent bitter taste and reducing their palatability. Roasting reduces the anti-nutritional factors in chestnut. This study was conducted to compare the effects of pan and microwave roasting on physicochemical, functional, rheological and antioxidant properties of sweet chestnut. Antioxidant activity was determined using DPPH inhibition activity, reducing power, and total phenolic content. Structural analysis was carried out using FT-IR analysis. Protein, fat, and ash contents displayed insignificant (P > 0.05) variations. "L" value decreased from 90.66 to 81.43, whereas, "a" and "b" values increased from 0.02 to 0.90 and 11.99 to 20.5, respectively, upon roasting. Significant (P < 0.05) increase in water absorption capacity (1.32-3.39 g/g), oil absorption capacity (1.22-1.63 g/g), and antioxidant properties was observed following roasting. Flour obtained from roasted chestnuts exhibited a significant decrease in light transmittance, foaming, and pasting properties. Higher gelatinization temperatures and lower enthalpies were reported in microwave and pan roasted chestnut flours. Roasting also reduced the viscoelastic behavior of native sweet chestnut and changed the transmittance of identical functional groups as revealed by FT-IR analysis.

γ-Irradiation of oat grain - Effect on physico-chemical, structural, thermal, and antioxidant properties of extracted starch.

Three different varieties of oat grains, Sabzaar, SKO-20, SKO-90 maintained at the moisture level of 12% were γ-irradiated at four different dosage levels - 5, 10, 15, and 20kGy. Starch was extracted and its physicochemical, structural, thermal, and antioxidant properties were studied. Amongst the physico-chemical properties, syneresis, solubility index, swelling index and light transmittance values showed a varied significance from their native counterparts. Irradiation also had an effect on RVA profiles which exhibited a decrease in peak, trough, final and set back viscosities whereas the pasting temperatures showed a significant (P≤0.05) decline. The exposure of hydroxyl groups in starch chain due to irradiation was confirmed via ATR FT-IR. γ-Irradiation resulted in the formation of ridges on the surface of starch as revealed from SEM. Irradiation resulted in a significant improvement in antioxidant activity of the extracted starches.

The possible nomenclature of encapsulated products.

The field of encapsulation is being explored widely and new information is not uncommon. However, the basic principles remain the same. Highlighting the importance of the variables in encapsulated products could help improve them for different applications. A separate nomenclature for encapsulated products would not only highlight important variables for producing better encapsulated products but might be helpful from their marketing point-of-view. Nomenclature of encapsulated products has potential in the production, properties, applications, economy, etc. of the final product. It could also help the general public understand more about what they are purchasing, and choose between options claiming the same or similar properties. The nomenclature proposed here is based on four variables (size, wall material, active ingredients and techniques for developing the encapsulated product) employed in the preparation of encapsulated products for different applications.

Effect of dual modification of sonication and γ-irradiation on physicochemical and functional properties of lentil (Lens culinaris L.) starch.

Starch isolated from lentil was subjected to two treatments namely sonication and, a dual treatment of sonication and irradiation at a dose of 5kGy. Lentil yielded 26.12±1.56g starch/100g of lentil. Chemical composition of native starch revealed 7.83±0.28% moisture, 0.23±0.30% protein, 0.35±0.05% fat and 0.10±0.00% ash. The results revealed that pasting properties of lentil starch were not affected upon sonication. However, these decreased significantly (p≤0.05) upon dual treatments. Amylose content of native starch was 31.16±1.80g/100g which showed a decrease upon sonication and dual treatments. Sonication and dual treatments (sonication and irradiation) decreased hunter 'L' value while 'a' and 'b' values showed an increase. Syneresis decreased more or less insignificantly upon sonication. However, a significant decrease in syneresis was observed after 120h storage following dual treatments. Sonication did not decrease the functional properties significantly while as dual treatment induced a significant decrease in functional properties. FT-IR analysis revealed a decrease in the intensities of OH, CH and OC stretches and CH2 bending upon sonication and dual treatments.

Extraction optimization of mucilage from Basil (Ocimum basilicum L.) seeds using response surface methodology.

Aqueous extraction of basil seed mucilage was optimized using response surface methodology. A Central Composite Rotatable Design (CCRD) for modeling of three independent variables: temperature (40-91 °C); extraction time (1.6-3.3 h) and water/seed ratio (18:1-77:1) was used to study the response for yield. Experimental values for extraction yield ranged from 7.86 to 20.5 g/100 g. Extraction yield was significantly (P < 0.05) affected by all the variables. Temperature and water/seed ratio were found to have pronounced effect while the extraction time was found to have minor possible effects. Graphical optimization determined the optimal conditions for the extraction of mucilage. The optimal condition predicted an extraction yield of 20.49 g/100 g at 56.7 °C, 1.6 h, and a water/seed ratio of 66.84:1. Optimal conditions were determined to obtain highest extraction yield. Results indicated that water/seed ratio was the most significant parameter, followed by temperature and time.

Physico-chemical, structural, pasting and thermal properties of starches of fourteen Himalayan rice cultivars.

Starch of fourteen rice cultivars grown in Himalayan region were evaluated for physico-chemical, structural, pasting and thermal properties. The rice cultivars selected showed a wide variation in apparent amylose content (AAC), ranging between 10.76%-26.87%, highest in CH-1039 and lowest in SKAU-292 starch. There were ten low, three intermediate and one high AAC rice. Resistant starch content varied significantly among the rice cultivars, ranging from 6.00% to 19.60%. Generally, high ACC starches presented high contents of resistant starch. Water absorption capacity (80.10-130.32%), swelling (5.73-9.61g/g) and solubility (0.037-0.090g/g) indices varied significantly among the rice cultivars. The rice starch granule morphology showed polyhedral or irregular shapes and granular sizes in the range of 1.8-6.7µm in different rice starches. Pasting profile of starch varied significantly among the rice cultivars, probably due to variations in their AAC. Thermal properties of the starches ranged considerably among different rice cultivars: onset temperature of gelatinization, To (58.25-72.49°C), peak temperature of gelatinization, Tp (69.93-93.26°C), conclusion temperature of gelatinization, Tc (97.28±8.28-112.16°C) and gelatinization enthalpy ΔHG (14.29-29.63J/g). The ATR-FTIR spectroscopy of rice starches identified most of the α-1→4 glucosidic linkages within the absorption bands of 1149-1023cm-1.