Intact Grains Research Articles

Understanding Pre- and Post-Milling Crack Formation in Rice Grain

HighlightsCracking and subsequent breakage of rice kernels reduces the marketability and profitability of rice.Pre-milling cracks in rice kernels cause breakage during milling, thereby reducing consumer acceptability.Three types of post-milling cracks reported are: surface, internal, and Hanasaki cracks.Post-milling cracks can be minimized throughout the supply chain.Abstract. Rice is consumed as intact grain, and any broken grains are discounted from the main marketable product. Breakage of rice mainly arises from cracks formed in the endosperm before or after milling. The cracks are formed by stress gradients that arise due to moisture absorption or desorption by grains. As a result of such stress, cracks mostly develop in a direction perpendicular to the length of the grain, making it less physically resistant to the stresses of milling, handling, and soaking processes. Until now, research into rice cracking has mainly focused on minimizing breakage during milling, and no significant knowledge is available on the impact and mechanisms of post-milling cracking and/or breakage and its effect on the downstream quality of rice. This article aims to review the existing information on the causes of rice cracking before and after milling. Keywords: Breakage, Crack, Drying, Glass transition temperature, Hanasaki, Head rice yield, Rice, Tempering.

Insight into the effects of moisture and layer build-up on the formation of lead soaps using micro-ATR-FTIR spectroscopic imaging of complex painted stratigraphies

Metal soaps are formed in paint layers thorough the reaction of metal ions of pigments and fatty acids of organic binders. In this study, micro-ATR-FTIR spectroscopic imaging was used to analyse the formation of lead soaps in oil-based paint layers in relation to their exposure to moisture sources. The investigations were carried out on authentic samples of complex stratigraphies from cold painted terracotta statues (Sacred Mount, Varallo, UNESCO) and different IR-active lead white pigments, organic materials, and lead soaps were discriminated. The saponification of selected paint layers was correlated to the conservation history, the manufacturing technique, and the build-up of layers. The presence of hydrophilic layers within the stratigraphy and their role as a further water source are discussed. Furthermore, the modifications experienced by lead-based pigments from the core of an intact grain of pigment towards the newly formed decay phases were investigated via a novel approach based on shift of the peak for the corresponding spectral bands and their integrated absorbance in the ATR-FTIR spectra. Qualitative information on the spatial distribution from the chemical images was combined with quantitative information on the peak shift to evaluate the different manufacture (lead carbonate, basic lead carbonate) or the extent of decay undergone by the lead-based pigments as a function of their grain size, contiguous layers, and moisture source. Similar results, having a high impact on heritage science and analytical chemistry, allow developing up-to-date conservation strategies by connecting an advanced knowledge of the materials to the social and conservation history of artefacts.

Dietary Patterns, Diabetes, and Aging

Several studies have suggested that eating patterns are associated with healthy aging and lower risk of diseases such as diabetes. The purpose of this paper is to review recent publications about dietary patterns, diabetes, and aging. The most robust research available on dietary patterns to reduce the risk of diabetes mainly indicates Mediterranean-style, DASH diet, vegetarian or vegan, and low-carb diet plans. An optimal dietary pattern for healthy aging and the treatment of diabetes should emphasize plant-based food (vegetables, beans, nuts and seeds, fruits, and whole intact grains), fish and other seafood, olive oil as the principal source of dietary fat; low-fat dairy products (mainly yoghurt and cheese) in low to moderate amounts; minimized consumption of refined grains; and preference of whole foods over highly processed foods. Further research on this topic is needed.

The agroecology of an early state: new results from Hattusha

The discovery of a large underground silo complex with spectacular intact grain stores at the Late Bronze Age Hittite capital of Hattusha in Turkey provides a unique snapshot of the mobilisation of crop production by the Hittite state. A combination of primary archaeobotanical analysis, crop stable isotope determinations and functional weed ecology reveals new insights into Hittite cultivation strategies, featuring a range of relatively low-input, extensive production regimes for hulled wheats and hulled barley. Taxation of extensively produced grain in the sixteenth century BC reveals how an ancient state sought to sustain itself, providing wider implications for the politics and ecology of territorially expansive states in Western Asia and beyond.

Reducing the cadmium, inorganic arsenic and dimethylarsinic acid content of rice through food-safe chemical cooking pre-treatment

Cadmium, inorganic arsenic and, potentially, dimethyl arsenic acid are carcinogens widely elevated in rice. Here it was identified that the food-safe and common cadmium chelator citric acid efficiently removed cadmium from intact grain via pre-soaking procedure, while also reducing arsenic species. A twostep pre-soaking stage was developed whereby rice was first incubated, at ambient temperature, in 1 M citric acid for 12 h, and then in 1 M calcium carbonate for another 12 h, the latter step to neutralize pH, followed by cooking. When 10 different individual types of rice were processed in such a way this resulted in removal rates of 79% for cadmium, 81% for inorganic arsenic and a 66% for DMA. The technology is particularly suitable for bulk food processing and could be deployed in the most cadmium and arsenic impacted regions where rice is a staple.

Frass produced by the primary pest Rhyzopertha dominica supports the population growth of the secondary stored product pests Oryzaephilus surinamensis, Tribolium castaneum, and T. confusum.

Primary pests such as Rhyzoperta dominica may increase the contents of dockage, dust, and frass in grain mass. Although it has been suggested that frass can affect the population growth of stored product pests and ecological interactions among primary and secondary pests in stored grain, this has not been validated experimentally. Therefore, this work experimentally tested the hypothesis that R. dominica wheat frass may support population increases in secondary pests such as Tribolium confusum, T. castaneum, and Oryzaephilus surinamensis for the first time. The effect of frass on secondary pest performance was compared with the effects of various physical qualities of wheat grain (i.e., intact grain kernels, grain fragments, flour, grain + frass) and an artificially enriched control diet (milled wheat kernels, oat flakes, and yeast). The results showed that the clean intact grain kernels did not support the population growth of any tested species, and the nutrient-rich control diet provided the best support. Frass was a significantly better food medium for O. surinamensis and T. castaneum than flour or cracked grain, while T. confusum performed equally well on flour and frass. Our results showed that in terms of food quality and suitability for the tested species, frass occupied an intermediate position between the optimized breeding diet and simple uniform cereal diets such as cracked grain or flour. The results suggest that (i) the wheat frass of primary pest R. dominica is a riskier food source for the development of the tested secondary pests than intact or cracked wheat grain or flour; (ii) frass has the potential to positively influence interspecific interactions between R. dominica and the tested secondary pests; and (iii) wheat grain should be cleaned if increases in R. dominica populations and/or accumulated frass are detected.

Viability of near infrared spectroscopy for a rapid analysis of the bioactive compounds in intact cocoa bean husk

The potential of the cocoa bean husk (CBH) as a natural source of bioactive compounds is ever-increasing. In this work, its bioactive compounds and antioxidant activity were analyzed using near infrared spectroscopy in samples of CBH. Beans were harvested and fermented in a Mexican gene bank. Reference data on total sugars, total phenols, phenolic compounds, theobromine, and antioxidant activity were correlated with the intact husk and bean spectra. The Modified Partial Least Square regression method (MPLSR) was used to develop calibrations. Good calibration statistics were obtained for total sugars (r2 = 0.90), theobromine (r2 = 0.83) and total phenols (r2 = 0.81) in data related to the CBH spectra, with a ratio of standard deviation/standard error of cross validation (RPD) of 3.16, 2.39 and 2.28, respectively. Acceptable calibrations for the estimation of bioactive compounds in CBH were obtained for the first time from the spectra of intact grain samples. Industries interested in bioactive compounds from CBH could use this technology as an easy and fast method to predict their contents, while avoiding the inconvenient de-husking process.

Harnessing particle disintegration of cooked rice grains for predicting glycaemic index

This study investigated the particle disintegration of cooked milled rice during in vitro digestion to identify its potential for rapidly predicting glycaemic index (GI). Milled grains and flour of rice with varying GI were cooked, stirred and subjected to digestion followed by kinetics analyses. Despite variations in physicochemical parameters (typically amylose content), flours showed a single-phase-digestion rate (k, ∼0.12 min−1) which did not vary significantly between varieties. In contrast, intact grains were disintegrated into small/intermediate (d < 30 μm, 30 < d < 300 μm) and large (d > 300 μm) particles. The small/intermediate particles comprising 50–70 % starch were initially-digested (0−20 min) at a fast k-f (∼0.05−0.10 min−1), which enabled to differentiate rice digestibility; whereas the large was latter-digested (20–180 min) at a slow k–s (∼0.04 min−1). The sum-ratio of disintegrated-particle 0−300 μm (Q-300) correlated positively with clinical GI values, allowing for a digestibility prediction of intact milled rice grain.

Automated recognition by multiple convolutional neural networks of modern, fossil, intact and damaged pollen grains

Pollen grains are valuable paleoclimate and paleovegetation proxies which require extensive knowledge of morphotypes and long acquisition time under the microscope. The abundance of damaged, folded, and broken pollen grains in the fossil register and sometimes also in modern soil and sediment samples, has so far prevented automation of pollen identification. Recent improvements in machine learning, however, have allowed reconsidering this approach. Here we present an automated approach which is capable of assisting palynologists with poorly preserved pollen samples. Called multi-CNNs, this approach is based on multiple convolutional neural networks (CNNs) integrated in a decision tree system. To test it, we built a system designed for three botanical families very common in the modern and fossil pollen assemblages of Eastern Africa, namely Amaranthaceae, Poaceae, and Cyperaceae. Our system was tested on stacked optical images of 8 pollen types (6 Amaranthaceae, 1 Poaceae, 1 Cyperaceae) using a training dataset of 1102 intact pollen grains and three validation datasets of intact (276 grains), damaged (223 grains), and fossil pollen (97 grains). We show that our system successfully recognizes intact, damaged, and fossil pollen grains with very low misclassification rates of 0%, 2.8%, and 3.7%, respectively. The use of augmentation on stacked optical images during the training increases classification accuracy. Following a palynologist's approach, our system allows grains without obvious characters to be classified into a class of high taxonomic level or as indeterminable pollen. This is the first software able to process grains with a wide range of taphonomical stages, which makes it the first truly applicable to automated pollen identification of fossil material.

Optimization of Agitation and Kinetic Studies on Proanthocyanidin Compound Extraction from Red Sorghum Grains in Agitated Vessel

Proanthocyanidin extraction for antioxidant material from intact red sorghum grains in agitated vessel had been investigated. The optimization and the appropriate kinetic evaluation were useful to conduct the engineering design of the developed process. Concentrations of the proanthocyanidin compounds in the aqueous extract were affected by the agitation speed and extraction time. The objectives of this research were to determine the optimum values of agitation speed and time for getting maximum extraction performance and to develop the appropriate kinetic model for illustrating the extraction phenomena. This research also evaluated the characteristics of the obtained extract. The optimum conditions of extraction were determined using Response Surface Methodology. The concentration of proanthocyanidin compound in the extract was predicted to be maximum at 405.05 rotations per minute (rpm) of agitation speed and 133.03 minutes of extraction time. The values of R2 of the regression equations were 99.45%. In the kinetic modeling, the mechanistic model turns to be much more accurate than the second order kinetic. The extract from the optimum process had 0.837 mg/ml of proanthocyanidin concentration and was proven to be effective in scavenging 64.02% of free radicals in the 100 μM DPPH in 30 minutes.

Real-time pollen monitoring using digital holography

Abstract. We present the first validation of the Swisens Poleno, currently the only operational automatic pollen monitoring system based on digital holography. The device provides in-flight images of all coarse aerosols, and here we develop a two-step classification algorithm that uses these images to identify a range of pollen taxa. Deterministic criteria based on the shape of the particle are applied to initially distinguish between intact pollen grains and other coarse particulate matter. This first level of discrimination identifies pollen with an accuracy of 96 %. Thereafter, individual pollen taxa are recognized using supervised learning techniques. The algorithm is trained using data obtained by inserting known pollen types into the device, and out of eight pollen taxa six can be identified with an accuracy of above 90 %. In addition to the ability to correctly identify aerosols, an automatic pollen monitoring system needs to be able to correctly determine particle concentrations. To further verify the device, controlled chamber experiments using polystyrene latex beads were performed. This provided reference aerosols with traceable particle size and number concentrations in order to ensure particle size and sampling volume were correctly characterized.

Acetylation of intact white rice grains to alter the physicochemical properties

The effect of acetylation of milled rice grains of selected varieties (TDK 8, YRW 4, Reiziq, Amber 33, and SHZ 2) with varying apparent amylose contents (3.8–26.6%) on their physicochemical properties was investigated. Milled rice samples were treated with different acetic anhydride concentrations (0.004–0.04 g per 100 g of milled rice samples in 225 mL of water). Results showed that glutinous (TDK 8), very low amylose (YRW 4) and low amylose containing varieties (Reiziq) were prone to acetylation even with 0.004 g of acetic anhydride. X-ray diffraction patterns showed an increase in the crystallinity in acetylated samples and formation of V-type crystals, suggesting the possible interaction of acetic anhydride with starch. Acetylation of rice grains resulted in reduced peak and final viscosities and gel strength, particularly in glutinous (TDK 8) and very low amylose (YRW 4) rice. Differential calorimetric study showed that acetic anhydride treatment resulted in reduced thermal transition temperatures and enthalpy of all varieties. Although increase in the retrogradation thermal temperatures was observed, the enthalpy of retrogradation was reduced with increasing acetylation, suggesting that the extent of starch retrogradation was lower in all varieties with more prominent reduction in the glutinous type. Furthermore, the texture of cooked acetic anhydride treated rice grains was less hard and showed more adhesiveness. This study demonstrated that the acetylation of rice grains (instead of flour) was successfully achieved, showing the potential of applying acetylation to alter the textural, pasting, thermal and retrogradation properties of rice.

Review of the Sensory and Physico-Chemical Properties of Red and White Wheat: Which Makes the Best Whole Grain?

Establishing sensory and physico-chemical differences between products made from red and white wheat may guide the choice of wheat for use in whole grain and high fibre products. As sensory acceptance is key to consumption, this scoping review aimed to document sensory and physico-chemical research demonstrating quantitative differences in red and white wheat and the associated bran. The following databases were systematically searched following the PRISMA protocol: PubMed, Medline, Scopus, CINHAL and ScienceDirect (1990–2019). Of 16 studies, 13 were sensory studies with 529 participants (six of which included quantitative analysis) and three additional quantitative studies. Overall, 10 studies were in favour of white wheat (seven sensory studies, two focused on quantitative analysis and two with additional quantitative studies). Whole grain (wholemeal) bread, pita bread, crackers, noodles, tortillas, flour, intact grains and bran were examined. Aside from the seed coat colour, levels of bound versus free phenolic compounds and polyphenol oxidase activity appeared most responsible for the differences in red and white wheat. Ensuring the sample size for sensory studies are large enough to detect between-group preferences and linking to physico-chemical analysis are recommended. Attention to blinding techniques in sensory testing and use of food products realistically and consistently prepared with commercial potential are also suggested. This scoping review provides confidence in preference for white wheat for whole grain products, particularly for breads, tortillas and in the choice of white wheat for products suitable for the Asian market.

Whole pearl millet feeding does not impair performance and nutrient digestibility in 28-day-old broiler chickens.

The effects of varying inclusion levels of whole grain millet in millet-soya bean-based diets on growth performance, gizzard development, digesta characteristics and nutrient digestion in broiler chicken were investigated. Starter (0-14days) and grower (15-28days) broiler chicken diets containing pearl millet at 500 and 540g/kg diet, respectively, were formulated. The diets comprised of 0%, 20%, 40%, 60%, 80% and 100% of millet incorporated as whole grain. One-day-old unsexed Arbor Acres Plus chicks (n=540) were allotted to the experimental diets in a completely randomized design with the diets and water provided ad libitum for 28days. Each treatment was replicated seven times, and each replicate had 12 chicks. Results showed that daily live weight gain and feed conversion ratio of chickens on the whole millet grain diets compared favourably with chicken on the control in both starter and grower phases, while feed intake reduced quadratically (p<.05) with increased whole grain millet levels in the starter phase. Morphological and structural characteristics of the gizzard and small intestine and intestinal digesta pH and viscosity were also unaffected (p>.05) by whole grain millet inclusion levels. However, the weight of intact millet grain in gizzard increased linearly (p<.001) with whole grain millet inclusion in the diets. Dietary whole grain millet inclusion also consistently lowered (p<.05) jejunal and ileal maltase and sucrase activities, but did not influence (p>.05) pancreatic amylase activity. Ileal crude protein and starch digestibility increased, while ileal energy digestibility decreased significantly (p<.05) with whole grain millet inclusion. Whole grain millet inclusion in broiler starter and grower diets up to 500-540g/kg did not negatively impact on broiler chicken performance.

Coupled chemo-mechanical modeling of fracture in polycrystalline cathode for lithium-ion battery

A thermodynamically consistent multi-physics framework has been developed to understand the chemo-mechanical interplay towards fracture behavior of polycrystalline microstructure along with the current collector. Adopting non-equilibrium thermodynamics, and considering bulk and interfaces as separate systems, the coupled governing equations are derived. The proposed framework accounts the plastic deformation of the host lattice and the substrate. A chemo-mechanical cohesive zone model (CZM) has been formulated to simultaneously capture the decohesion and transport across grain boundaries, while classical CZM is used between the cathode/substrate interface. Using numerical framework, grain-boundary width is initially calibrated to ensure transport of Li-ions through intact grain boundaries. The proposed numerical scheme has been verified with semi-analytical model for cylindrical cathode particle in the presence of an interface. Further, thin film polycrystalline cathode along with current collector has been examined to explore the role of various interactions (one way or two way) between the diffusion and stresses on the emergent voltage profile for an electrochemical cycle. In particular, the chemical and mechanical driving forces have been investigated together with evolution of grain boundary fracture and their consequences on the insertion/extraction of Li-ions from the host lattices. In addition, we address the mechanical failure and attendant voltage profiles for various microstructural and electrochemical parameters (i.e., grain size and charge rate). The present framework can provide better design perspective for the development of heterogeneous electrode system with improved mechanical integrity under fully coupled chemo-mechanical environment.

Effects of different drying methods on appearance, microstructure, bioactive compounds and aroma compounds of saffron (Crocus sativus L.)

In our study, saffron stigmas were subjected to vacuum drying (VD), microwave drying (MD), oven drying (OD), infrared drying (ID) and freeze drying (FD), respectively. Quality attributed of the dried samples were compared in terms of appearance color, microstructure, bioactive compounds and aroma compounds. Results showed that FD, ID and MD were the better drying methods to preserve bioactive or aroma compounds, respectively. Meanwhile, FD retained good appearance color, complete initial cell structure and intact pollen grains, ID led to shortest drying time (0.7 h). However, FD time was the longest (47 h), in addition, the cost and energy consumption of FD and ID were relatively high. Therefore, considering about energy consumption and the quality of saffron, MD might be the most suitable method for both keeping content of crocins and aroma components, and its drying time was short (1.9 h).

Population Growth of Alphitobius diaperinus (Coleoptera: Tenebrionidae) on Various Commodities.

The lesser mealworm, Alphitobius diaperinus (Panzer), is a serious pest, but at the same time has been authorized in European Union (EU) for feed in aquaculture. In this study, we investigated, in laboratory bioassays, the population growth of this species, on a wide variety of commodities. In four series of bioassays, we studied the development of A. diaperinus population on various intact cereal grains, on soft wheat grains with different percentages of cracked kernels, on non-grain amylaceous commodities and on a variety of non-amylaceous commodities. Briefly, 20 g of each commodity were put separately inside plastic cylindrical vials. Then, 20 A. diaperinus adults were placed inside each vial and all vials were incubated at 30°C and 55% r.h. After 30 d, the vials were opened and the progeny production was evaluated. Alphitobius diaperinus showed a clear preference in amylaceous commodities, but in contrast, poor development was recorded on the non-amylaceous commodities tested. Hence, it developed well in most of the cereal intact grains tested, with the hard and soft wheat being the most suitable. Additionally, most non-grain amylaceous commodities were suitable, to a various degree, for the population growth of A. diaperinus. The increase of the percentage of cracked wheat positively affected the population growth of A. diaperinus. To our knowledge, this is the first study that examined the suitability of a wide range of commodities for the population growth of A. diaperinus.

Glycemic Index and Microstructure Evaluation of Four Cereal Grain Foods.

To determine the glycemic index (GI) of selected cereals and association with their microstructure. The GI of whole grain pilaf (WGP), instant brown rice (IBR), whole maize ugali (MWU), and refined maize ugali (RMU) was assessed in a randomized trial. Fourteen healthy participants with mean age of 25 years were administered 50g portions of available carbohydrates from glucose and various test foods after an overnight fast on separate occasions. Capillary blood samples of participants were used to measure blood glucose over 2 hr. The GI was calculated as per standard protocol. The microstructure of test foods, determined by scanning electron microscopy was evaluated to understand the measured GI values. The GI (mean ± standard error) of IBR was the highest (87.8±6.8) followed by RMU (74.7±6.5) and WMU (71.4±5.1). WGP had medium GI (58.9±5.1; P <0.01vs. IBR). Microstructure examination of IBR revealed disruption of bran layer and presence of fissures indicating loss of intactness of bran. Stereozoom images for WGP revealed intact bran and germ. For RMU and WMU, the grain was milled leading to loss of integrity. IBR, RMU, and WMU have high GI values, which is likely due to disruption of bran layer, endosperm modification (IBR), and loss of grain matrix (WMU, RMU). WGP has medium GI probably due to fairly intact bran and germ. PRACTICAL APPLICATION: Wholegrain or whole meal flour may not necessarily be low in glycemic index (GI; low GI <55; medium 55 to 69 and high GI ≥70). "Ugali" a commonly consumed cereal staple food in Tanzania made from either refined or whole meal maize flour was found to be a high GI food. Intact whole grain foods, such as whole grain pilaf (mixed intact whole grains) is a healthier alternative to milled whole grains such as whole meal maize flour. Instant quick cooking brown rice exhibited a high GI, due to the processing method, suggesting that regular brown rice may be a healthier option.

A Mechanistic Model of Mass Transfer in the Extraction of Bioactive Compounds from Intact Sorghum Pericarp

The extraction of phytochemical compounds from intact red sorghum grains was developed as an alternative process for producing bioactive material in the pharmaceutical industry. A mechanistic model is needed to better understand the process and enable predictive simulations for designing commercial-scale extraction systems. This paper presents a mathematical model for predicting phytochemical concentrations in the solvent and inside the pericarp of the grain at different positions during the extraction. The model is based on the mass transfer mechanism from inside the pericarp to its solid surface by diffusion, and then from the surface to a solvent during the extraction of bioactive compounds. It was numerically solved while using finite-difference approximation. The parameters considered were effective diffusivity inside the pericarp (Dep), mass transfer coefficient from the pericarp surface to the solvent (kc), and distribution coefficient (H). The model simulates the extraction performance, including the yield and bioactive compounds’ concentrations in the extract and inside the pericarp at various positions and times. A sensitivity analysis of the changes in each involved parameter provided sufficient information for increasing the performance of the model. A validation test that compared the results of the simulation with those of established analytical solutions showed that the model has high accuracy. Hence, the model can be applied in quantitative evaluations to improve productivity in the pharmaceutical industry.

High-throughput method for preliminary screening of high dietary fiber rice

Dietary fiber has several benefits for humans, and the development of healthier rice with an improved dietary fiber composition has attracted increasing amounts of attention. Based on the method of AOAC 2002.02, we developed a simplified method to screen polished rice containing high total dietary fiber (TDF). Mutant cw with a high TDF content could be distinguished easily from R7954 (indica) and Nipponbare (japonica) by the digestion-resistant phenotype, which is characterized as an almost intact grain after hydrolysis by pepsin, pancreatic α-amylase and amyloglucosidase. The individuals identified from the F2 population showed digestion resistance all had TDF content higher than 5%, while those without a digestion-resistant phenotype had TDF content lower than 5%. The phenotype of digestion resistance could be a valuable index for identifying rice with higher TDF content, and the identification of this phenotype provides a simplified, economical and high throughput method for high TDF rice breeding.