Effect of puffing on physical and antioxidant properties of brown rice

Effect of Sprouted Buckwheat on Glycemic Index and Quality of Reconstituted Rice

This study utilized sprouted buckwheat as the main component and aimed to optimize its combination with other grains to produce reconstituted rice with enhanced taste and a reduced glycemic index (GI). The optimal blend comprised wheat flour, sprouted buckwheat flour, black rice flour, and purple potato flour in a ratio of 34.5:28.8:26.7:10.0. Based on this blend, the reconstituted rice processed through extrusion puffing exhibited a purple-black hue; meanwhile, the instant reconstituted rice, produced through further microwave puffing, displayed a reddish-brown color. both imparted a rich cereal flavor. The starch in both types of rice exhibited a V-shaped structure with lower relative crystallinity. Compared to commercial rice, the reconstituted rice and instant reconstituted rice contained higher levels of flavonoids, polyphenols, and other flavor compounds, along with 1.63-fold and 1.75-fold more proteins, respectively. The GI values of the reconstituted rice and the instant reconstituted rice were 68.86 and 69.47, respectively; thus, they are medium-GI foods that can alleviate the increase in blood glucose levels.

Process optimization of wheat flour crisp puffing by radio frequency and the accompanying property changes of starch

This research performed the process optimization of wheat flour crisp puffing by radio frequency (RF) and investigated the accompanying property changes of starch. Experiments were performed in a 6 kW, 27.12 MHz pilot-scale RF system. The results showed that the volume expansion was highest (220%) when the conditions were employed as follows: electrode gap (115 mm); height of the sample (55 mm); initial moisture content of the sample (30%). Under these conditions, the samples were puffed at 120 s by RF, and changes in the starch properties were further observed. The results showed that the structure of the starch was destroyed, changing from oval and spherical in shape to fragmented. The crystal type of the starch changed from A to A + V types. Its crystal order was reduced, and the Fourier-infrared spectrum showed that the ratio of (1048/1022) cm-1 decreased from 1.142 to 1.047. The crystallinity decreased from 48.27% to 17.57%. These changes will help starch digestion and absorption in human body. These results indicated that RF puffing could become a potential development method for puffed snacks. PRACTICAL APPLICATION: In this study, the processes of radio frequency puffing wheat flour chips were optimized, and the changes of starch properties during puffing were studied. Therefore, this research provided a theoretical basis for the industrial application of radio frequency puffing.

Expanded porous-starch matrix as an alternative to porous starch granule: Present status, challenges, and future prospects

Exposing the hydrated-soft-starch matrix of intact grain or reconstituted flour dough to a high-temperature-short-time (HTST) leads to rapid vapor generation that facilitates high-pressure build-up in its elastic matrix linked to large deformation and expansion. The expanded starch matrix at high temperatures dries up quickly by flash vaporization of water, which causes loss of its structural flexibility and imparts a porous and rigid structure of the expanded porous starch matrix (EPSM). EPSM, with abundant pores in its construction, offers adsorptive effectiveness, solubility, swelling ability, mechanical strength, and thermal stability. It can be a sustainable and easy-to-construct alternative to porous starch (PS) in food and pharmaceutical applications. This review is a comparative study of PS and EPSM on their preparation methods, structure, and physicochemical properties, finding compatibility and addressing challenges in recommending EPSM as an alternative to PS in adsorbing, dispersing, stabilizing, and delivering active ingredients in a controlled and efficient way.

Active compounds: A new direction for rice value addition

The development of rice active compounds is conducive to improving the added value of rice. This paper focused on the types and effects of active compounds in rice. Furthermore, it summarized the effect of rice storage and processing technology on rice active compounds. We conclude the following: Rice contains a large number of active compounds that are beneficial to humans. At present, the research on the action mechanism of rice active compounds on the human body is not deep enough, and the ability to deeply process rice is insufficient, greatly limiting the development of the rice active compound industry. To maximize the added value of rice, it is necessary to establish a dedicated preservation and processing technology system based on the physicochemical properties of the required active compounds. Additionally, attention should be paid to the development and application of composite technologies during the development of the rice active compound industry.

Effects of degree of milling on nutritional quality, functional characteristics and volatile compounds of brown rice tea

This study investigated the effects of rice preparation using different degrees of milling (DOM) from 0% to 13% on the nutritional composition, functional properties, major volatile compounds and safety of brown rice tea (BRT). We found that 2% DOM reduced 52.33% of acrylamide and 31.88% of fluorescent AGEs. When DOM was increased from 0% to 13%, the total phenolic content (TPC) of brown rice tea decreased by 48.12%, and the total flavonoid content (TFC) and condensed tannin content (CTC) also decreased significantly, with the smallest decrease at 2% DOM. In addition, the inhibitory activities of α-amylase, α-glucosidase and pancreatic lipase as well as the antioxidant activity also decreased gradually. Analysis by electronic nose and gas chromatography-mass spectrometry (GC-MS) showed that alkanes, furans, aldehydes, pyrazines and alcohols were the major volatiles in BRT, with 2% DOM having the greatest retention of aroma compounds. An orthogonal partial least squares discriminant analysis (OPLS-DA) and VIP score (VIP > 1 and p < 0.05) analysis were used to screen 25 flavor substances that contributed to the differences in BRT aroma of different DOMs. These results suggest that 2% milled BRT can improve safety and palatability while maximizing the retention of flavor compounds and nutrients. The findings of this study contribute to an enhanced understanding of the dynamics of changes and preservation of aroma compounds and nutrients present during the processing of BRT.

Effect of fiber-bound polyphenols from highland barley on lipid oxidation products of cooked pork during in vitro gastrointestinal digestion

BACKGROUND

The gastrointestinal (GI) tract is a major site of lipid oxidation, and the lipid oxidation products are related to an increased risk of various chronic diseases. In this study, the inhibition capacity of bound-polyphenol rich insoluble dietary fiber (BP-IDF) from highland barley (HB) to lipid oxidation was evaluated during simulated GI digestion.

RESULTS

We found that the level of lipid hydroperoxides (LOOH) and aldehydes were significantly inhibited when highland barley bound-polyphenol rich insoluble dietary fiber (HBBP-IDF) co-digestion with cooked pork. The lipid oxidation products were more effectively scavenged during simulated gastric digestion, with inhibition of 77.4% for LOOH, 52.3% for malondialdehyde, 46.5% for 4-hydroxy-2-hexenal and 48.7% for 4-hydroxy-2-nonenel, respectively. The fiber-bound polyphenols are the principal scavengers of lipid oxidation products.

CONCLUSION

These findings suggest that HBBP-IDF could be used as a functional ingredient able to scavenge lipid oxidation products across the GI tract. © 2023 Society of Chemical Industry.

Novel infrared puffing: Effect on physicochemical attributes of puffed rice (Oryza sativa L.)

The effect of novel infrared (IR) puffing and various IR powers (350, 450, and 550 Watts [W]) at various distances (10, 20, and 30 cm) on physicochemical characteristics of puffed rice (puffing properties, color, total phenolic content [TPC], antioxidant activity, peroxide value, and morphology) was investigated. By reducing the distance and increasing the IR power, the volume puffing was significantly increased (p < .05), and bulk density was significantly decreased (p < .05) but there was no significant difference in the length/breadth ratio. The IR puffing effect on color, the TPC, antioxidant activity, and food compounds' analysis through Fourier transform infrared (FTIR) spectra were significant (p < .05) during IR puffing. The scanning electron microscopy (SEM) images showed that by increasing the IR power and decreasing the sample distance from the IR source, the size of protrusions was increased (the volume of the protrusions). The maximum increase in the protrusions size was observed in 10 cm distance and 550 W power of IR. This is the first report on the IR puffing of rice and according to the results, the IR puffing technology has a high efficiency at the rice puffing.

Effects of extrusion temperature and puffing technique on physical and functional properties of purpled third-generation snack after heat treatment

This work aimed to investigate the effects of extrusion temperature (100 105 and 110 °C) and puffing technique (microwaving (210, 420 and 560 W.) and deep frying (170 and 190 °C)) on physical and functional properties of third-generation snack containing purple sweet potato and butterfly pea flower. Snack qualities in terms of physical properties (expansion ratio, bulk density, color and texture) and functional properties (total anthocyanin content, total phenolic content and antioxidant capacity) were subsequently determined. The results showed that extrusion temperature did not significantly affect the color of snack pellets. However, it significantly affected the functional properties of the snack pellets. Snack pellet produced from extruder at 110 °C contained significantly higher functional properties when compared to those extruded at 100 and 105 °C (p < 0.05). In addition, the study of the puffing method indicated that an increase of microwave power level and frying temperature resulted in a decrease of hardness. On the other hand, the increase of microwave power level and frying temperature caused an increase of antioxidant capacity in the puffed snacks. Moreover, microwave puffing could help preserve the color and antioxidant capacity better than deep frying. Especially, microwaved snack had total anthocyanin content twice more than that puffed by frying.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05234-x.

The Effect of High Pressure Processing on Textural, Bioactive and Digestibility Properties of Cooked Kimberley Large Kabuli Chickpeas

High pressure processing is a non-thermal method for preservation of various foods while retaining nutritional value and can be utilized for the development of ready-to-eat products. This original research investigated the effects of high pressure processing for development of a ready-to eat chickpea product using Australian kabuli chickpeas. Three pressure levels (200, 400, and 600 MPA) and two treatment times (1 and 5 min) were selected to provide six distinct samples. When compared to the conventionally cooked chickpeas, high pressure processed chickpeas had a more desirable texture due to decrease in firmness, chewiness, and gumminess. The general nutrient composition and individual mineral content were not affected by high pressure processing, however, a significant increase in the slowly digestible starch from 50.53 to 60.92 g/100 g starch and a concomitant decrease in rapidly digestible starch (11.10-8.73 g/100 g starch) as well as resistant starch (50.53-30.35 g/100 g starch) content was observed. Increased starch digestibility due to high pressure processing was recorded, whereas in vitro protein digestibility was unaffected. Significant effects of high pressure processing on the polyphenol content and antioxidant activities (DPPH, ABTS and ORAC) were observed, with the sample treated at the highest pressure for the longest duration (600 MPa, 5 min) showing the lowest values. These findings suggest that high pressure processing could be utilized to produce a functional, ready to eat kabuli chickpea product with increased levels of beneficial slowly digestible starch.

Optimized Roasting Conditions of Germinated Wheat for a Novel Cereal Beverage and Its Sensory Properties

The objective of this study was to investigate the possibility of using germinated wheat as a nutritionally improved novel cereal beverage. To enhance the health-related functionality of a germinated wheat beverage (GWB), the roasting time and temperature of germinated wheat were optimized using a central composite design and response surface methodology. The optimum roasting conditions were determined as roasting temperature of 180 °C and roasting time of 44.56 min, resulting in maximum total flavonoid content (0.74 mg CE/g), total phenolic content (1.95 mg GE/g), 2,2-diphnyl-1-picrylhydrazyl (DPPH) radical scavenging activity (5.10 μM TE/g), Trolox equivalent antioxidant capacity (9.45 mM TE/g), and γ-aminobutyric acid content (2.25 mg/g). The germinated wheat roasted with optimum conditions was prepared in two types of GWB (hot and cold), and the sensory characteristics were tested by consumers (n = 102). The cold GWB showed relatively high preferences compared to hot GWB in appearance, odor, taste, and overall acceptabilities. In the intensity results of the sensory properties of GWB, the cold GWB tended to have stronger browning, grain odor, and nutty taste than the hot GWB. Conclusively, this study showed that optimizing the roasting conditions of germinated wheat could achieve desirable sensory properties and consumer acceptance while improving the health-related functionality of GWB.

Effect of Sand-Frying-Triggered Puffing on the Multi-Scale Structure and Physicochemical Properties of Cassava Starch in Dry Gel

This study revealed the underlying mechanisms involved in the puffing process of dried cassava starch gel by exploring the development of the puffed structure of gel upon sand-frying, chiefly focused on the changes in the multi-scale structure and the physicochemical properties of starch. The results suggested that the sand-frying-induced puffing proceeded very fast, completed in about twenty seconds, which could be described as a two-phase pattern including the warming up (0~6 s) and puffing (7~18 s) stages. In the first stage, no significant changes occurred to the structure or appearance of the starch gel. In the second stage, the cells in the gel network structure were expanded until burst, which brought about a decrease in moisture content, bulk density, and hardness, as well as the increase in porosity and crispness when the surface temperature of gel reached glass transition temperature of 125.28 °C. Upon sand-frying puffing, the crystalline melting and molecular degradation of starch happened simultaneously, of which the latter mainly occurred in the first stage. Along with the increase of puffing time, the thermal stability, peak viscosity, and final viscosity of starch gradually decreased, while the water solubility index increased. Knowing the underlying mechanisms of this process might help manufacturers produce a better quality of starch-based puffed products.

Consumer Acceptance of Brown and White Rice Varieties

Rice is consumed as a staple food by more than half of the world's population. Due to a higher fibre and micronutrient content, brown rice is more nutritious than white rice, but the consumption of brown rice is significantly lower than that of white rice, primarily due to sensory attributes. Therefore, the present research aimed to identify the sensory attributes which drive liking of Australian-grown brown and white rice varieties. Participants (n = 139) tasted and scored (9-point hedonic scale) their liking (i.e., overall liking, aroma, colour and texture) of brown and white rice types of Jasmine (Kyeema), Low GI (Doongara), and Medium grain rice (Amaroo). In addition, participants scored aroma, colour, hardness, fluffiness, stickiness, and chewiness, on Just About Right Scales. A within-subjects crossover design with randomised order (William's Latin Square design) was used with six repeated samples for liking and Just About Right scales. Penalty analyses were applied to determine the relative influence of perception of sensory attributes on consumer liking of the rice varieties. Across all varieties, white rice was liked more than brown rice due to the texture and colour, and Jasmine rice was preferred over Low GI and Medium Grain. Rice texture (hardness and chewiness) was the most important sensory attribute among all rice varieties and aroma was important for driving of liking between white rice varieties.

Design and development of a machine for continuous popping and puffing of grains

Popping/puffing have been traditionally practiced for enhancing storage life, improving organoleptic properties and ease of incorporation in ready-to-eat-foods. Currently, batch type sand and electric popping/puffing machines involving conduction mode of heat transfer are employed. The major drawbacks of these methods are high-energy consumption, scorching of grains, non-uniform product quality, contamination (by sand/ash) and problems in scale-up. Since fluidization is known to increase heat and mass transfer, a continuous fluidized popping/puffing machine (capacity 10-20 kg/h) involving convective mode of heat transfer is designed/developed. Hot-flue gas generating from burning of LPG was used as the eco-friendly fuel. Process parameters such as expansion ratio, fluidization velocity, terminal velocity, carry over velocity, bulk density and voidage were estimated for un-popped and popped/puffed rice, maize, jowar (sorghum) and paddy. Fluidization and carry over velocities for these grains were in the range of 4.18-5.78 m/s and 2.15-6.18 m/s, respectively. Based on the terminal velocity of the grains and volumetric air flow rate of the blower, fluidization chamber diameter was arrived. Chamber diameter of 0.15 m was found to be sufficient to generate required air velocity of 6.89 m/s which met the fluidization and carry over velocities of popped/puffed grains. The designed fluidization chamber was analyzed for heat and mass transfer during popping/puffing. Convective heat and mass transfer coefficients were estimated to be in the range of 103-187 W/m2 °C and 0.124-0.162 m/s, respectively. Theoretical values for total heat and mass transfer were similar to the experimental values.

Understanding the deterioration of fresh brown rice noodles from the macro and micro perspectives

The microbial compositions, quality characteristics, and structural changes in fresh brown rice noodles (FBRN) during storage were investigated. Total plate count and mold and yeast counts increased while the pH decreased during storage. Metagenomic sequencing revealed that the microbial composition of FBRN changed throughout storage. A comprehensive investigation of the variation in lipid content demonstrated that hydrolytic rancidity was responsible for lipid deterioration. LF-NMR showed an increase in the proportion of bound water and a decrease in the proportion of free water in FBRN. Moreover, significant changes in edible qualities were observed. The cooking loss increased three-fold and noodles hardness reduced by approximately 23%. Further, the high initial aldehyde content of FBRN diminished almost completely, while that of alcohols and esters increased, leading to significant flavor deterioration. The correlation and factor analysis suggested that the TPC and MY counts could be used as key indicators of FBRN deterioration.

Effect of thermal treatment on the physicochemical, ultrastructural and nutritional characteristics of whole grain highland barley

Highland barley (HB) was subjected to three thermal treatments (heat fluidization, microwave, and baking) and assessed for physicochemical, ultrastructural and nutritional properties. After thermal treatments, the hardness, bulk density, thousand kernel weight, length/breadth ratio, and color difference decreased significantly, while puffing index increased. Meanwhile, the formation of fissure was observed in the appearance. Microstructure images illustrated that numerous micropores were evenly distributed in the endosperm structure, and aleurone layer cells were deformed by compression. Furthermore, a dramatically disruption of endosperm cell walls and slightly deformation of outer layers were observed by confocal laser scanning microscopy. Moreover, a notably decrease in total phenolics (14.02%-36.91%), total flavonoids (25.28%-44.94%), and bound phenolics (8.99%-27.53%) was detected, while free phenolics (8.81%-43.40%), β-glucan extractability (4.71%-43.66%), antioxidant activity (71.87%-349.77%), and reducing power (3.05%-56.13%) increased significantly. Greatest increase in nutritional values was caused by heat fluidization, which possessed the potential for development of ready-to-eat functional foods.

Effect of Different Pre-Treatments on Antinutrients and Antioxidants of Rice Bean (Vigna umbellata)

Rice bean (Vigna umbellata) is a legume that belongs to Vigna genus. Native to Indo-Chinese region, it is considered to be an ‘under-utilized’ or ‘orphan’ crop. Rice bean is known to possess high nutritional potential and antioxidant activity. But the use of rice bean supplementation in routine diet is limited despite its high nutritional profile due to the presence of non-nutritional factors. Thus, various pre-treatments like soaking, germination, oven roasting, sand roasting, boiling and pressure cooking at different time and temperature were carried out to reduce the anti-nutritional content of rice bean and to study its effect on antioxidant activity and phytochemical content. All the pre-treatments were able to significantly reduce the anti-nutrient content in rice bean, but germination showed the maximum reduction. Also germinated rice bean showed the maximum antioxidant potential and maximum content of total phenols, total flavonoids, vitamin C and carotenoids. Rice bean has been underutilized so far, owing to its antinutrient content and low popularity. This experiment attempted to use low cost processing to reduce the content of antinutrients and track the antioxidant content in rice bean. The concluded processing could be adopted for commercial applications for dietary supplementation.

Evaluation of sensory, physicochemical properties and Consumer preference of black rice and their products

This study was aimed to evaluate the physicochemical, textural, sensory and antioxidative attributes of various rice products such as boiled rice, beaten rice, popped rice, puffed rice and raw milled rice, prepared from the Indian black rice cultivars Chakha (CH), Kalobhat (KB), Mamihunger (MA) and Manipuri Black (MN). A popular white rice variety Swarna Sub-1 (SW) was considered as control. Significant differences in most of the physicochemical and cooking parameters of raw rice were observed across different cultivars. The head rice recovery, amylose content, elongation ratio (ER) and kernel length after cooking of MA were most satisfactory among the black rice cultivars and are found to be 50.67%, 17.6%, 1.87 and 10.10 mm respectively, while popped rice of MA recorded highest length (10.83 mm) and elongation ratio (ER; 2.01). MA showed the highest adhesiveness (11.18 mJ) in boiled rice but hardness (183.53 N) was medium in raw rice. Other textural quality varied differentially according to the various products and cultivars. The highest a* value was obtained from puffed rice of MA (6.61) but L value was highest in raw rice of MN. Popped and boiled rice of MA displayed higher DPPH-antioxidant activity (88.74% and 84.74% respectively) as compared to all other products. The raw rice of KB registered higher anthocyanin (57.23 mg/100 g) content while boiled rice of SW recorded the least (0.21 mg/100 g). A survey on the consumer preference of these products indicated that boiled rice was usually preferred in lunch and dinner by most of the consumers whiles other products in breakfast. With respect to most of the traits, MA showed the good potential for rice Industry as well as for breeding material.

Modelling the physical properties change of canned glutinous rice porridge during cooking

In this study, we modeled the water absorption, softening and shear viscosity change kinetics of canned rice porridge during cooking as well as estimated the thermodynamic properties involved in hydration. Moreover, the internal microstructure of rice kernels was observed under different hydrothermal conditions. During cooking, the water absorption and shear viscosity alteration rate increased with temperature, whereas the softening rate decreased. However, the temperature did not significantly affect the equilibrium value of the physical properties. The variation tendencies of the moisture content and hardness of the kernels could be expressed satisfactorily by the exponential and the generalized exponential models. The porridge shear viscosity variations fitted the sigmoidal and its generalized models. Thermodynamic parameters (enthalpy, entropy and Gibbs free energy) revealed that the hydration process was non-spontaneous and exothermic. Furthermore, scanning electron microscopy images and the results of the X-ray diffraction analysis showed the microstructure of the kernels during cooking, and the kernels formed a homogeneous mesh structure at earlier times during the initial stage at higher temperatures. These findings would provide valuable information for the optimization of canned rice porridge production.

Comparison of Germination-Parboiling, Freeze-Thaw Cycle and High Pressure Processing on Phytochemical Content and Antioxidant Activity in Brown Rice Evaluated after Cooking and In-Vitro Digestion

Three treatments, namely germination-parboiling (PG), freeze-thaw cycle (FTC) and high pressure processing (HPP) were compared for phytochemical content and antioxidant activity of brown rice (BR). These were determined in raw (uncooked), cooked, and in-vitro digested BR and compared with those from untreated BR and white rice (WR). PG showed the highest retention of phytochemicals after cooking (87–100%) while it dropped to 59–72% with FTC and 64–76% with HPP. After in-vitro digestion, the highest amount of phenolics was found in PG-24 h and flavonoids in FTC for two cycles. The antioxidant activity, as determined by oxygen radical absorbance capacity and ABTS methods, showed the highest value to be associated with in-vitro digested sample of PG-24 h, and lowest in WR. The results of this study show that these three treatments could improve or retain the phenolic content and antioxidant activity in cooked BR after in-vitro digestion.

Innovative processing techniques for altering the physicochemical properties of wholegrain brown rice (Oryza sativa L.) - opportunities for enhancing food quality and health attributes

Rice is a globally important staple consumed by billions of people, and recently there has been considerable interest in promoting the consumption of wholegrain brown rice (WBR) due to its obvious advantages over polished rice in metabolically protective activities. This work highlights the effects of innovative processing technologies on the quality and functional properties of WBR in comparison with traditional approaches; and it is aimed at establishing a quantitative and/or qualitative link between physicochemical changes and high-efficient processing methods. Compared with thermal treatments, applications of innovative nonthermal techniques, such as high hydrostatic pressure (HHP), pulsed electric fields (PEF), ultrasound and cold plasma, are not limited to modifying physicochemical properties of WBR grains, since improvements in nutritional and functional components as well as a reduction in anti-nutritional factors can also be achieved through inducing related biochemical transformation. Much information about processing methods and parameters which influence WBR quality changes has been obtained, but simultaneously achieving the product stabilization and functionality of processed WBR grains requires a comprehensive evaluation of all the quality changes induced by different processing procedures as well as quantitative insights into the relationship between the changes and processing variables.