Rice-Shaped Extruded Kernels: Physical, Sensory, and Nutritional Properties

Apparent amylose content positively influences the quality of extruded fortified rice kernels

The present research studies the impact of apparent amylose content (AAC) on the quality of fortified rice kernels (FRK), a health food designed to combat iron deficiency anemia by fortifying with iron, folic acid, and vitamin B12. Five FRK formulations with varying AAC (0.46-23.89 %) were prepared, and AAC influence on the extruder-system parameter and physicochemical, cooking, and textural properties of FRK was investigated. The torque, die-pressure, length, redness, and cooking time increased with an increase in AAC and were in the range of 12.55-22.81 Nm, 58.31-88.96 bar, 4.58-5.09 mm, 0.35-1.15, and 6.1-11.2 min, respectively. The other parameters, such as the breadth, whiteness index, and cooking loss decreased with an increase in AAC. Except for cohesiveness, all other textural properties of cooked FRK increased with an increase in AAC. These correlations of the FRK properties with AAC were confirmed through multivariate analysis. SEM, XRD, FTIR, and rheology supported the observed AAC trends in FRK properties. SEM showed a reduction in pores and cracks with an increase in AAC. The XRD and FTIR showed an increase in crystallinity with an increase in AAC due to better gelatinization leading to rapid retrogradation. This leads to better physical, cooking, and textural properties of FRK.

The use of hydrogel structures in production of extruded rice and investigation of its qualitative characteristics

The aim of this study was to investigate the quality parameters of extruded rice containing hydrogel and comparing with natural rice (Hashemi variety rice). Extruded rice was produced with composite hydrogel (gellan, xanthan and sodium alginate) at the concentrations of 0.0 (control sample), gellan (0.5%)-alginate (0.5%) (GA1), gellan (1%)-alginate (1%) (GA2), gellan (0.5%)-alginate (0.5%)-xanthan (0.1%) (GAX 1%), and gellan (1%)-alginate (1%)-xanthan (0.2%) (GAX2%). The use of hydrogels had no significant effect on moisture content, ash content, cooking time, and color properties of extruded rice (p ≥ .05). In contrast, hydrogel significantly increased water absorption ratio (WAR), water solubility index (WSI), water absorption index (WAI), and textural properties (p ˂ .05) of extruded rice. This observation supports the highest score found for extruded rice containing GA2% and GAX2% in sensory properties, which were similar to natural rice. GA2% rice sample showed the similar texture characteristic, cooking feature, and color parameter to natural rice, ultimately, showing better organoleptic properties.

Development of rice analogues fortified with iron, folic acid and Vitamin A

Fortified rice analogues were developed utilising the broken-rice fortified with selected micronutrients like iron, folic acid and Vitamin A. The purpose of this study was to investigate the feasibility of fortifying rice analogues with micronutrients and retention after extrusion and cooking. Cold extruder operated at 55 rpm screw speed and 1.5 kg/h feed rate was used for the study. The composite flour prepared using broken-rice flour, sodium alginate (1%), water (30%) and micronutrient mix was extruded through rice shaped die at barrel temperature of 60 °C. The level of fortifying nutrient ready mix (FNRM) was statistically optimised based on retention of nutrients after extrusion and cooking. The retention results for iron was observed to be 73.3 to 91.3 per cent after cooking whereas folic acid and Vitamin A being sensitive to processing and culinary operations were 44.2 to 60.4 and 10.1 to 12.4 per cent, respectively. Statistical optimisation resulted 150 per cent of FNRM could supply nutrient levels nearing the standards with the desirability of 0.835. The production cost was calculated as Rs.53.50 per kg whereas, increase in the cost of raw rice mixed with fortified analogues @ 1:50 ratio was about Rs.1.00 per kg with benefit-cost ratio of 1.22:1.

Rice as a vehicle for micronutrient fortification: a systematic review of micronutrient retention, organoleptic properties, and consumer acceptability

CONTEXT

Previous reviews have focused on evaluating the efficacy and effectiveness of rice fortification, despite the need to also understand the outcomes of micronutrient retention, organoleptic properties, and acceptability to inform nutrition programs.

OBJECTIVE

This systematic review aims to consolidate existing evidence on micronutrient retention, organoleptic properties, and acceptability of fortified rice.

DATA SOURCES

Eligible articles were identified from 22 electronic databases and personal referrals and reviews.

STUDY SELECTION

Studies on rice fortified via extrusion or coating technologies were included in the review if they reported outcomes in at least 1 of 3 domains: micronutrient retention, organoleptic or physicochemical properties, and acceptability (evaluated by sensory tests and consumer surveys). Any years of publication and study populations were considered for inclusion. A total of 15 391 articles were screened, yielding 49 for inclusion.

DATA EXTRACTION

Study results were summarized descriptively through discussions by intervention conditions, study population, measurement methods, and key findings. The included studies were independently reviewed by 2 of the 3 authors, and all 3 authors reached consensus on the quality and major findings from the included articles.

RESULTS

Extrusion and coating fortification technologies were found to be comparable across studies that assessed retention, organoleptic properties, and acceptability. Cooking fortified rice in excess water increased micronutrient loss for both technologies. Fortified kernels containing ferric pyrophosphate, zinc oxide, or zinc sulfate showed the most positive results for all outcomes reviewed, while retention rates of vitamin A in multiple-micronutrient-fortified rice were variable.

CONCLUSIONS

The current practice of fortifying rice with ferric pyrophosphate provides high micronutrient stability and results in rice with organoleptic properties and consumer acceptance levels comparable to those of unfortified milled rice, although it presents challenges regarding the effect of vitamin A-fortified rice on vitamin A status.

Considerations for improvising fortified extruded rice products

Micronutrient fortification of rice by extrusion is an effective strategy to enhance micronutrient levels within rice-consuming individuals. The success of extrusion-based fortification is associated with micronutrient retention, enhanced bioavailability, low postprocessing losses, prolonged storage stability, and minimal sensory changes. The success of an optimally fortified product is primarily reliant upon the compositional considerations, but many attributes of extrudates can be indebted to the processing parameters too. Hence, an exhaustive investigation of this technology has been taken-up here, emphasizing on the compositional parameters in association with process parameters, which influence the final quality attributes like nutrient stability, bioavailability, and sensory properties. Based on these attributes of the end product, a collected data have been presented here to bring out the optimal compositional requirements. These together with cooking processes, extrusion process parameters, and storage conditions will enable formulate a product with enhanced sensory acceptance, better retention during cooking and storage, improved texture, and acceptable color. This review will thus help to optimize a need-based product, its quality, and enhance benefits of fortified extruded rice products.

Effect of carboxymethylcellulose and locust bean gums on some of physicochemical, mechanical, and textural properties of extruded rice

Extrusion is a composite process consisting of many different unit operations such as mixing, cooking, pasting, and molding. In this process, the raw material is forced through a tiny opening to be transformed into a product with a desired and unique shape, texture, color, and taste. In combination with different amounts and types of additives, this technique can result in functional food products for a broad range of people suffering from micronutrient deficiency. The hydrocolloid compounds are now employed to improve the texture and performance properties of many food products. Therefore, this study scrutinized the effects of carboxymethylcellulose and locust bean gums at different levels (0.5, 0.75, and 1%) alone or in combination with each other on chemical, physical, mechanical, and textural properties of extruded rice in comparison with the qualitative properties of the control rice. A completely random design was used along with three replications to analyze the test results. Then the means were compared through Duncan's multiple range test at (α = 5%). According to the results, addition of gums increased moisture, ash, total color difference, water absorption capacity, solubility, failure force, rupture energy, elasticity module, and toughness when reduced lateral expansion was compared to the control. Moreover, the addition of gums after the cooking process increased cooking loss, texture hardness, chewability, and elasticity of the specimens in comparison with the control. According to the results of pre- and post-cooking tests, the specimens containing locust (0.75%) and carboxymethylcellulose (0.75%) gums were the best treatments.