Use of Protein Content, Amylose Content, and RVA Parameters to Evaluate the Taste Quality of Rice

Taste quality of rice is the key to its value. However, it is greatly affected by rice types and the environment. It is a complex but necessary factor to accurately evaluate the taste quality of various types of rice in different environments. In this study, 7 different types of rice with different taste values were used as materials, and 12 nitrogen fertilizer treatments were applied to obtain 84 different rice taste values. We used protein content, amylose content, and RVA to evaluate changes in the taste value of rice. Rice with high taste value tended to have higher amylose content, peak viscosity, hold viscosity, final viscosity, and breakdown, as well as lower protein content, pasting temperature, and peak time. Protein and amylose contents affected the taste value of rice by affecting the RVA profiles except for setback. For high and low taste-value rice types, protein content could explain 66.8 and 42.9% of the variation in taste value, respectively. In the case of medium taste-value type, protein content was not enough to evaluate the taste quality of rice. Stickiness could explain 59.6% of the variation in taste value. When the protein content of rice was less than 6.61% or greater than 9.34%, it could be used to reflect the taste quality of rice. When the protein content was in between the two, protein content was not enough to reflect the taste quality of rice. Our results suggested that protein content could better reflect the taste quality change for rice, which provided a theoretical and technical basis for the accurate evaluation of the taste value of various types of rice.

Quasi Emulsion Solvent Diffusion Modification of Underutilized Chenopodium album Starch and its Characterization

The present study was designed to investigate the changes occur on Chenopodium album starch (CAS) after modification through quasi emulsion solvent diffusion (QESD) method. Modification of starch was carried out by HCl (0.1, 0.25, 0.50, 0.75 and 1M) followed by precipitation. The QESD modification significantly reduced the amylose content, water absorption capacity, oil absorption capacity, solubility as well as swelling power of treated starch. Gelatinization behaviour of modified starch showed an increase in pasting temperature. The SEM images showed the formation of regular and spherical shaped larger starch particles. There was an improvement in crystallinity from 20.01 to 29.86% after modification as shown in X-ray analysis. Overall, it indicates that QESD treatment results into formation of spherical crystalline agglomerates.

Starch synthesis and gelatinization properties of potato tubers

ABSTRACT: Biosynthesis is the only source of potato starch which is an important raw material for food processing, modified starch and biomass energy. However, it is not clear about the evolution of starch synthesis with tuber development in potato. The present study evaluated the differences of starch synthesis and gelatinization properties of potato tubers with different starch content. Relative to cultivars of medium and low starch content, cultivars of high starch content showed significantly higher SBEII gene expression, AGPase and SSS enzyme activity, and total starch content after middle stage of starch accumulation, and had smaller average starch granule size during whole process of tuber development, and had higher pasting temperature before late stages of tuber growth, and had lower pasting temperature after middle stage of starch accumulation. Path analysis showed that, after middle stage of starch accumulation, effects on starch gelatinization of cultivars with high, medium and low starch content represented starch synthesis enzyme activity > starch accumulation > starch granule distribution > starch synthesis enzyme gene expression, starch synthesis enzyme gene expression > starch synthesis enzyme activity > starch accumulation > starch granule distribution, starch synthesis enzyme gene expression > starch granule distribution > starch synthesis enzyme activity > starch accumulation, respectively. In the study, phases existed in the starch biosynthesis of potato tuber, and the starch quality and its formation process were different among varieties with different starch content. The findings might contribute to starch application and potato industries.

Proximate composition, pasting and functional properties of composite flour blends from cassava and chia seeds flour

The study established the proximate composition, pasting, and functional properties of cassava flour (CF) blended with chia seeds flour (CSF). Composite flour was prepared by blending CF with CSF in the ratios of 95:05, 90:10, 85:15, 80:20, and 75:25 with CF and CSF used as controls, respectively. The effect of blending significantly (p < 0.05) increased protein, fat, fibre, and ash contents as CSF increased. On other hand, moisture and carbohydrate contents decreased significantly. Pasting properties of composite flour blends decreased significantly (p < 0.05) as the incorporation of CSF increased and a noticeable change was observed for composite flour (75:25) except for peak time and pasting temperature. Functional properties of water absorption capacity (WAC) of CSF were significantly different with CF and composite flour blends. Oil absorption capacity (OAC) of CF and CSF were significantly different, while the composite flour blends had varied OAC due to the inclusion of the different amounts of CSF. The swelling capacity (SC) of CF and CSF were not significantly different, but composite flour blends were significantly different from both CSF and CF. The least gelation concentration (LGC) and bulk density (BD) increased significantly as chia seeds increased. Increased concentration of chia CSF in the composite flour blends showed to alter the functional properties. This study recommends composite flour 75:25 for processing semiliquid products like porridge due to reduced pasting properties values that may be associated with increased energy density compared to CF.

Characterization and utilization of nixtamalised rice flours in the production of cake

In an attempt to provide an alternate rice processing technique and enhance its nutritional quality, Faro 52 (Upland) and Nerica 8 (Lowland) rice grains were subjected to nixtamalisation involving cooking and soaking in a lime solution. The proximate composition, functional properties and pasting characteristics of the nixtamalised and nonnixtamalised rice flours were evaluated. Cakes produced with the rice flours were also subjected to sensory evaluation. Nixtamalisation significantly increased the protein content of upland (NUPRF) and lowland (NLLRF) rice flours by 28.19% and 27.80%, respectively. Nixtamalisation also enhanced the water absorption capacity of the rice flours, while the oil absorption capacity increased significantly. Pasting viscosities of all the nixtamalised flours were lower than their non-nixtamalised samples, while the pasting temperature increased. Nixtamalised rice cakes were not significantly different in colour, texture, flavour and overall acceptability from non-nixtamalised rice cakes. Nixtamalisation may be beneficial in rice processing for enhanced nutritional content and functionality, and the flour may be useful as a thickener and binder in food systems and the production of acceptable cakes.

Effects of Fermented Maize Residue Addition on the Physico-chemical and Sensory Properties of Chin-Chin

Chin-Chin, a traditional Nigerian snack was prepared utilizing wheat-fermented maize residue composite flour at 0 – 30% replacement levels. Effects of this addition on the functional and pasting properties of the flour composite was evaluated. The snack produced was also evaluated for its sensory attributes, proximate composition and invitro-protein digestibility (IVPD). Functional properties results showed an increase in water absorption capacity (WAC), a decrease in oil absorption capacity (OAC), decrease in Bulk Density (BD), swelling power and solubility index with residue addition. Pasting property results showed a drop in the value of peak, trough, breakdown and final viscosity with substitution while set back viscosity increased.Peak temperature decreased, but values for pasting temperature showed no significant difference between the control and the blends. Results for sensory evaluation showed equal preference for overall acceptability. Proximate composition results showed residue addition led to an increase in crude fibre and protein content with a drop in the carbohydrate value. Residue addition did not increase protein digestibility. Addition of fermented maize residue in chin-chin production can be another way of utilizing the fibre rich by-product of the production of fermented maize starch.

Physicochemical Properties and Digestion Resistance of Acetylated Starch Obtained from Annealed Starch

One of the examples of physical starch modifications is the retention of a starch suspension in water having a temperature slightly lower than the pasting temperature (annealing). The aim of this study was to investigate the effect of the annealing process performed at various temperatures as the first stage of starch modification. The annealed starch preparations were then esterified using acetic acid anhydride. Finally, the annealed and acetylated starch preparations were determined for their properties. The annealing of starch before acetylation triggered changes in the properties of the modified preparations. It contributed to a higher degree of starch substitution with acetic acid residues and to the increased swelling power of starch. Both these properties were also affected by the annealing temperature. The highest resistance to amylolysis was found in the case of the starch preparation annealed at 53.5 °C and acetylated. The double modification involving annealing and acetylation processes increased the onset and end pasting temperatures compared to the acetylation alone. Similar observations were made for the consistency coefficient and yield point.

Assessment of Functional and Pasting Properties of Fresh Orange Maize Hybrids and Open-Pollinated Varieties as Influenced by Genotype, Harvesting Time, and Growing Location

The study evaluates the effects of genotype, maturity, and growing location on the functional and pasting properties of freshly harvested orange maize hybrids and open-pollinated varieties (OPVs). Eight fresh orange maize hybrid and eight fresh maize OPV, including the control, were harvested at three stages: 20, 27, and 34 days after planting (DAP). The freshly harvested maize samples were lyophilized and characterized for the pasting and functional properties using standard laboratory methods. The peak viscosity, final viscosity, and swelling power of the OPVs increased between 20 and 27 DAP. Additionally, the water absorption capacity increased between 20 and 27 DAP for the maize hybrids, with a decreasing trend between 27 and 34 DAP. However, genotypes 2, from the orange maize hybrid, and 5, amongst the OPV, were outstanding with the highest peak viscosities, indicating good final product quality. The combined ANOVA for the fresh orange maize hybrid and OPV showed a highly significant effect (p ≤ 0.01 and p ≤ 0.001) for the maturity and location on the pasting and functional properties except for the pasting temperature, final viscosity, and pasting time which showed no significant effect. In contrast, the location by genotypes by maturity interactions had no significant effects on the pasting and functional properties of the fresh maize hybrid and the orange OPV except only for the setback, which was highly significant at p ≤ 0.001. Nutritionists, food scientists, and maize breeders could use the information from this study to select the best maize genotypes at the appropriate harvesting period suitable for the production of the preferred maize-based products of consumers.

Pasting properties of jack bean (Canavalia ensiformis) modified starch with heat moisture treatment

Jack bean is a local legume that can grow in suboptimal land and potential to be developed in Indonesia. Jack bean seed has 33.32% of protein and 61.15% of carbohydrate so it can become a starch source for the food industry. Native starch has a limited application on food products because of its weak characteristics such as being unstable to heat and shear. Heat Moisture Treatment (HMT) starch modification is needed to overcome the weaknesses. HMT is a natural modification because it does not leave a chemical residue. The objective of this research was to investigate the effects of heat moisture treatment (HMT) with various moisture content and time on the pasting properties (peak, through, breakdown, final, setback viscosity, peak time, and peak temperature) of jack bean modified starch. This research used Factorial Completely Randomized Design (FCRD) with two factors, varying moisture content (27%, 30%, 33%) and time (10 h, 13 h, 16 h). The results show that the various moisture leads to increase peak-time, pasting temperature and decrease peak viscosity, through viscosity, breakdown, final and setback viscosity. In addition, higher HMT time could increase peak time, pasting temperature but decrease peak, trough, breakdown, final and setback viscosity.

Effects of Pectin on the Physicochemical Properties and Freeze-Thaw Stability of Waxy Rice Starch

In this study, the effects of the addition of pectin (PEC) on the physicochemical properties and freeze-thaw stability of waxy rice starch (WRS) were investigated. As PEC content increased, the pasting viscosity and pasting temperature of WRS significantly increased (p < 0.05), whereas its breakdown value and setback value decreased. Differential scanning calorimetry showed that the addition of PEC increased the gelatinization temperature of WRS, but decreased its gelatinization enthalpy. Rheological measurements indicated that the addition of PEC did not change the shear-thinning behavior of WRS–PEC blends, and the storage modulus and loss modulus were positively correlated with PEC content. Moreover, the textural parameter of WRS decreased with the increase in PEC content. Furthermore, the addition of PEC decreased the transmittance of starch paste, but enhanced the freeze-thaw stability of WRS to some extent. These results may contribute to the development of WRS-based food products.