Rapid Visco Analyzer Research Articles

Predicting wheat flour quality for making Japanese sponge cake using flour pasting properties as measured by the Rapid Visco Analyzer

AbstractBackground and ObjectivesThe objective of this study was to evaluate a series of Rapid Visco Analyzer (RVA) methods for their ability to produce results that were predictive of Japanese sponge cake (JSC) quality. Two solvents (water and 50% [w/w] sucrose in water) and two temperature profiles [Standard 1 (STD 1) and an internal cake temperature profile] were selected to run across a diverse set of flour samples from two crop years that possessed variable bake performance. The results were analyzed for predictive outcomes for JSC prepared using a mechanical fold method.FindingsThe solvent retention capacity (SRC) results did not show any significant trends with JSC quality. The RVA results from both profiles using water as the solvent did not show a significant correlation with JSC quality while the 50% (w/w) sucrose solvent was significantly correlated (p ≤ .01). The STD 1 and internal cake temperature profile batter pasting viscosity (BPV) using the sucrose solvent showed significant (p ≤ .01) correlations with mechanical folded JSC volume (r = .97), firmness (r = −.88), and overall score (r = .85).ConclusionsThe RVA BPV results showed that a 50% sucrose solvent could more accurately be used to predict and screen for JSC quality outcomes. Both RVA profiles could be used with a sucrose solvent to predict JSC quality. JSC volume and overall score showed significant positive correlations with BPV while firmness had a significant negative correlation.Significance and NoveltyThis research identified two RVA profiles that when paired with a 50% (w/w) sucrose solvent could be used to screen for JSC quality using less flour and taking less time than a bake test. This test could potentially assist breeders and millers in quicky screening flours for efficient decision making. This is the first time an RVA temperature profile that mimics the internal rise in temperature for a JSC during baking has been used to predict JSC quality. In addition, the STD 1 profile using the 50% (w/w) sucrose solvent has not been previously used to predict JSC quality.

Variation in amylose content in three rice variants predominantly influences the properties of sushi rice

Sushi rice is a ready-to-eat traditional Japanese dish seasoned with vinegar, sugar and salt that has gained popularity worldwide. There are many rice cultivars grown in the world which vary in their cooking, sensory, and processing quality. The aim of this study was to analyse chemical, physical, and functional properties of three rice varieties (Vietnamese, Italian, and Australian) to determine their suitability for sushi rice production. Rice was cooked using industry norms and vinegar was then added; samples with no vinegar were prepared for comparison. The rice was stored during 5 days at 4 °C after cooking for texture profile analysis and samples were taken on day 1 and day 5. Flour composition as well as amylose content, gelatinisation properties using differential scanning calorimeter, pasting properties using Rapid Visco Analyser, water absorption capacity (WAC), oil absorption capacity (OAC) and swelling power of extracted starch were determined. Results showed that the amylose content (16.51 to 21.37%) had a large impact on the functional and quality characteristics of the rice variants including texture, pasting, gelatinisation and WAC properties. Australian starch showed the highest amylose content, setback viscosity, final viscosity, pasting temperature and lowest gelatinisation temperature. The lower amylose content and gelatinisation temperature contributed to a softer texture in the Vietnamese rice samples over life. The added vinegar aided in keeping the texture soft during the shelf-life of the rice. Since sushi rice is usually prepared with vinegar, Italian and Vietnamese rice are better candidates for sushi rice based on their lower hardness after 5 days of storage when compared to the Australian variety.

Effect of lecithin on the complexation between different botanically sourced starches and lauric acid

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.

Nutritional Profiling of Underutilised Citrullus Lanatus Mucosospermus Seed Flour

The seed of Citrullus lanatus mucosospermus, known as egusi, is versatile and explored for its oil and flour functionality. Raw flour can be used as a raw material in a nutritional program due to its oil-rich, remarkably high protein content, and richness in omega-6 fatty acids. There is a need to explore eco-friendly defatting methods using the supercritical CO2 extraction method (SFECO2) to preserve this seed’s generic richness and to control the flour–oil ratio in processing formulations. The supercritical fluid extraction method uses temperature, pressure, and CO2 flow rate to determine the best yield and extraction parameters. Defatted egusi flour (DEF) was extracted using three runs. Firstly, at 60 °C, 30 g/h, and 450 bar (DEF1); secondly, at 55 °C, 30 g/h, and 600 bar (DEF2); and thirdly, extraction was performed at 75 °C, 30 g/h and 600 bar (DEF3). Trace and major elements were analysed using Agilent 7700 quadruple ICP-MS (Agilent Technologies Network, Palo Alto, CA, USA) and Thermo Cap 6200 ICP-AES (Thermo Scientific, Waltham, MA, USA), respectively. The sugar was separated on a gas chromatograph coupled to a Mass Selective Detector (MSD). The fundamental pasting property measurements were performed using a Rapid Visco Analyser RVA 4500 Perten instrument Sin 214 31208-45 Australia. Data analysis was conducted using IBM SPSS version 29 software (v. 2022). The protein content of defatted egusi flour ranged from 48.4 for DEF2 to 60.4% w/w for DEF1 and differed significantly, with a rich amino acid high in glutamine ranging from 9.8 to 12.9 g/100 g). DEF2 (512.0 cP) showed the highest peak viscosity and was the most viscous among the samples. Defatted flour with lower temperature and lower pressure (60 °C and 450 bar) offered the best nutritional properties, proffering defatted egusi flour from SFECO2, a novel flour for dietary programs.

Assessing Amylose Content with Iodine and Con A Methods, In Vivo Digestion Profile, and Thermal Properties of Amylosucrase-Treated Waxy Corn Starch.

In this study, waxy corn starch was modified with 230 U or 460 U of amylosucrase (AS) from Neisseria polysaccharea (NP) to elongate the glucan. The amylose content of the AS-modified starches was determined using iodine and concanavalin A (Con A) methods, and their in vivo digestion, thermal, swelling, and pasting properties were evaluated. The amylose content of AS-treated starches was not significantly different (p > 0.05) when using the Con A method but was significantly higher than that of non-AS-treated samples when using the iodine method. In vivo, rats fed AS-treated starch had significantly lower blood glucose levels at 15 min than other rats; rats fed 460 U AS had lower blood glucose levels at 30 and 60 min than non-AS-treated rats. DSC analysis revealed that AS-treated starches exhibited higher initial, melting, and completion temperatures. Minimal volume expansion was observed by swelling factor analysis, while a Rapid Visco Analyzer assessment revealed that they had higher pasting onset temperatures, lower peak viscosities, and no trough viscosity compared to native starch. The elongated glucans in AS-treated starch reinforced their crystalline structure and increased slowly digestible and enzyme-resistant starch content. Overall, AS-treated starch showed unique thermal properties and a reduced blood glucose index upon administration. This distinctive characteristic of NPAS-treated starch makes it a good candidate food or non-food material for cosmetic products, medical materials, and adhesives.

Use of Pea Proteins in High-Moisture Meat Analogs: Physicochemical Properties of Raw Formulations and Their Texturization Using Extrusion.

A new form of plant-based meat, known as 'high-moisture meat analogs' (HMMAs), is captivating the market because of its ability to mimic fresh, animal muscle meat. Utilizing pea protein in the formulation of HMMAs provides unique labeling opportunities, as peas are both "non-GMO" and low allergen. However, many of the commercial pea protein isolate (PPI) types differ in functionality, causing variation in product quality. Additionally, PPI inclusion has a major impact on final product texture. To understand the collective impact of these variables, two studies were completed. The first study compared four PPI types while the second study assessed differences in PPI inclusion amount (30-60%). Both studies were performed on a Wenger TX-52 extruder, equipped with a long-barrel cooling die. Rapid-visco analysis (RVA) and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated differences in protein solubility among the different PPI types. In general, lower protein solubility led to better product quality, based on visual evaluation. Cutting strength and texture profile analysis showed increasing PPI inclusion from 30-60% led to significantly higher product hardness (14,160-16,885 g) and toughness (36,690-46,195 g. s). PPI4 led to lower product toughness (26,110 and 33,725 g. s), compared to the other PPIs (44,620-60,965 g. s). Heat gelling capacity of PPI4 was also highest among PPI types, by way of least gelation concentration (LGC) and RVA. When compared against animal meat, using more PPI (50-60%) better mimicked the overall texture and firmness of beef steak and pork chops, while less PPI better represented a softer product like chicken breast. In summary, protein content and also functionality such as cold water solubility and heat gelation dictated texturization and final product quality. High cold water solubility and poor heat gelation properties led to excessive protein cross linking and thicker yet less laminated shell or surface layer. This led to lower cutting firmness and toughness, and less than desirable product texture as compared to animal meat benchmarks. On the other hand, pea proteins with less cold water solubility and higher propensity for heat gelation led to products with more laminated surface layer, and higher cutting test and texture profile analysis response. These relationships will be useful for plant-based meat manufacturers to better tailor their products and choice of ingredients.

Preparation and physicochemical properties: a new extruded rice using cassava starch and broken rice flour

With the increasing demand for nutrition and health, many researchers are trying to develop a rice product with lower aging rate and convenient nutrient fortification. Being composed of high amylopectin content, cassava starch (CS) shows a lower retrogradation tendency compared to rice starch. So, it has a broad application prospect to partially replace rice starch with CS in rice by extrusion technology. In this study, a new extruded rice (ER) was prepared by broken rice flour and CS using single-screw extruder through “improved extrusion cooking technology,” and the maximum addition level of CS in ER was 30%. Color parameters and texture profile analysis showed that ER was a little darker in appearance with lower hardness, adhesiveness and chewiness. Rapid visco analysis demonstrated that the viscosity of ER paste appeared earlier during the initial heating phase and displayed a lower retrogradation trend than normal rice in the cooling process. The gelatinization temperature and gelatinization enthalpy decreased with the increasing CS in ER, while the degree of gelatinization increased to 76.36% when the content of CS was 30% after extrusion. The X-ray diffraction patterns of control was typical A-type structure, while ER changed to V-type structure with a lower degree of crystallinity. The microstructure observation showed that ER exhibited a looser and more porous structure with increasing the content of CS, which facilitated easier cooking and nutritional enhancement.

Effects of storage conditions on chemistry and technological properties of different cultivars of Chickpea

The impact of storage conditions, such as 40 °C, high humidities (55% and 65%), and storage (360 days), on the nutritional value, pasting, and functional properties, color differences, and quality of protein and starch in five Chickpea (Cicer arietinum) cultivars (Crown, Royal, Sierra, Orion, and Frontier) was determined. The Sierra cultivar had the highest initial moisture content (MC, 7.7 ± 0.01%), and MC increased over time for all samples stored at 55% and 65% RH and 21 °C. Protein (PC), total starch (TSC), and fat (FC) contents changed in all cultivars during storage. Under the same storage conditions (65% RH and 40 °C treatment), the Frontier variety had significantly higher PC at day zero (24.0 ± 0% dwb) and 360 (23.9 ± 0.2% dwb) compared to other cultivars, while no significant differences existed between other cultivars. A general upward trend in the pasting data was observed for all cultivars of the 360-day stored samples. In contrast, the gel firmness of the gels formed during Rapid Visco Analysis (RVA) was lower for the 360-day samples. Emulsion capacity (EC) and Foaming capacity (FC) changed significantly in all samples over time under the effects of different variables. Color analysis revealed reduced yellowness in all samples during storage. Also, lightness values decreased over time, indicating seed darkening during storage. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed the disappearance of major protein bands around 37 and 55 kDa after 360 days, indicating protein aggregation and structural alterations. Fourier transform infrared spectroscopy (FTIR) of amide II structures indicated interactions and differences in the secondary structure of proteins in the samples stored for 360 days. Starch analysis via SEM revealed protein-coated starch granules, indicating protein-starch interactions occurred during storage. Harsh storage conditions (65% RH and 40 °C) significantly affected nutritional quality, functional and pasting properties, and protein chemistry of chickpeas and should be avoided for extended storage.

Protein isolates made in the laboratory versus the factory: A case study with mung bean and chickpea

AbstractProtein isolates deliver functionalities such as gelling, emulsifying, and foaming, and many recent publications are reporting the functionality of new protein isolates produced in the laboratory. Laboratory protein isolation processes are quite different to industrial processes, and therefore isolate functionalities are likely to be different. We examined some of the differences between laboratory isolates and commercial isolates of mung bean and chickpea protein (MPBI and CPPI). We tested solubility as a function of pH, dispersibility by static light scattering, and viscosity enhancement in a rapid visco analyzer (RVA). Thermal transitions were evaluated with differential scanning calorimetry (DSC), and powder morphology was examined by scanning electron microscopy (SEM). Laboratory isolates were more soluble (e.g. 54%–57% vs. 5%–45% at pH 8) and dispersible than commercial isolates, with the largest DSC endotherms, indicating the least denaturation. Among commercial isolates, we found large differences in solubility, thermal properties, and viscosity enhancement, and minor differences in dispersibility and powder morphology. The hydration protocol had a strong effect on solubility and DSC results, and a moderate effect on RVA results. Comparisons between isolates produced in different laboratories are currently hampered by the use of nonstandard empirical methods for certain functionalities, and we highlight standardized methods for measuring dispersibility and viscosity enhancement. Protein isolation processes affect isolate functionality via effects on protein denaturation and aggregation, and via the morphology and surface chemistry of isolate powders. This means that findings with laboratory isolates cannot necessarily be extrapolated to commercial counterparts but also indicates the power of process design to modulate isolate functionality.

New Insight into the Effects of Endogenous Protein and Lipids on the Enzymatic Digestion of Starch in Sorghum Flour.

The effects of endogenous lipids and protein in sorghum flour on starch digestion were studied following the depletion of lipids and/or protein and after the reconstitution of separated fractions. The removal of protein or lipids moderately increases the digestibility of starch in raw (uncooked) sorghum flour to values close to those for purified starch. Rapid Visco Analyzer data (as a model for the cooking process) show that cooked sorghum flours with lipids have a lower starch digestibility than those without lipids after RVA processing, due to the formation of starch-lipid complexes as evidenced by their higher final viscosity and larger enthalpy changes. Additionally, the formation of a starch-lipid-protein ternary complex was identified in cooked sorghum flour, rather than in a reconstituted ternary mixture, according to the unique cooling stage viscosity peak and a greater enthalpy of lipid complexes. After heating, the sorghum flour showed a lower digestibility than the depleted flours and the reconstituted flours. The results indicate that the natural organization of components in sorghum flour is an important factor in facilitating the interactions between starch, lipids, and protein during RVA processing and, in turn, reducing the starch digestion.

Evaluation of the quality and safety of commercial complementary foods: Implications for nutrient adequacy and conformance with national and international standards.

Optimal nutrition in early childhood increases growth and development while preventing morbidity and mortality in later life. This study focused on the quality and safety of 32 commercially produced complementary foods collected from supermarkets in Addis Ababa, Ethiopia. The proximate composition (moisture, protein, fat, crude fibre, and ash); and the mineral profile (calcium, iron, zinc, manganese, and magnesium) were determined using the AOAC method. The determination of antinutritional factors (Condensed tannin and oxalate) was done using a UV spectrophotometer. A rapid visco analyzer was used to measure the rheological property. The microbial load of commercially produced complimentary foods was identified using aerobic colony counts for mold and yeast. Labeling practice was evaluated using the WHO and Ethiopian standard tools. The results of proximate compositions were: protein (0.92-18.16 g/100g), fat (0.63-6.44 g/100g), crude fiber (1.04-13.2 g/100g), energy (410-337 kcal/100g), moisture (0.03-17 g/100g), and ash (0.60-4.67 g/100g). The protein and fat content of all the products is below international standards. Only three products met the standards for energy. Moisture and ash contents partially met the requirement, while all of the carbohydrate contents of the products fell under the specified standard. The lowest and highest mineral contents of the products were: Fe (1.38 to 15.10 mg/100g), Zn (0.64 to 6.78 mg/100g), Ca (30.55 to 364.45 mg/100g), Mg (1.2 to 34.2 mg/100g), and Mn (0.80 to 32 mg/100g). Based on these, 21.5% of the foods met the Fe standard, and 31.5% didn't meet the Zn standard. The Ca and Mg of all the products met the requirement. Except for one product, all met standards. The highest and lowest results for the tannin and oxalate content of the products were 49.20 to 90.09 mg/100g and 0.47 to 30.10 mg/100g, respectively and this shows that the products are below the permissible range for tannin and oxalate. The counts of yeast and mold were 0.00-2.95 log10 cfu/g and 0.00-2.91 log10 cfu/g, respectively. Only one product fell below the standard for yeast count, and none of the products showed a mold count that exceeded the standard. The final viscosity was 63.5-3476 RVU, and only 31.25% of the samples fell under the permissible peak viscosity range, of 83-250 RVU. Thus, regular monitoring of the raw material and processing trends and the inclusion of animal sources in the raw material are suggested for having well-enriched complementary foods. Regulatory bodies should also conduct frequent market surveillance to safeguard the health of the consumer.

Rice gelatinization temperature prediction using the rapid visco analyzer vis‐à‐vis the traditional DSC method

AbstractBackground and ObjectivesThe measurement of gelatinization temperatures (GTs) of rice using the Rapid Visco Analyzer (RVA) can be a more rapid and efficient method as compared to the traditional method of using Differential Scanning Calorimeter (DSC). The objective of this research was to determine the accuracy and precision of the RVA technique in comparison to the DSC method for measuring GTs of contemporary rice cultivars produced in Arkansas.FindingsRice samples analyzed using the RVA had GT that ranged from 70.48 ± 0.18°C to 75.72 ± 0.11°C, while the DSC‐analyzed samples had GT that ranged from 67.25 ± 0.18°C to 74.72 ± 0.64°C. The values of RVA GT consistently overestimated the values of the DSC‐GT, with the RVA GT values demonstrating higher precision. A calibration equation was developed to correct the overestimation of RVA GT values, and its validity was confirmed through data obtained from both laboratory‐scale tests and industry‐based analysis.ConclusionsThe method of using RVA can serve as a standalone approach for determining the GT of rice from various cultivars.Significance and NoveltyThis technique of using RVA can be beneficial to industrial and educational applications because it is less expensive, easier to follow, and more rapid in analysis as compared to DSC.

Evaluating high oleic soybean oil oleogels as shortening replacements: Impact on cookie dough, cookie attributes, and oxidative stability

AbstractIn this study, we explored the potential of oleogels to serve as a substitute for traditional shortening throughout the entire cookie production process. Specifically, oleogel was prepared using expeller‐pressed high oleic soybean oil (EPHOSO) with 10 wt% of either rice bran wax (RBX) or monoacylglycerol (MAG) to replace shortening in cookie making. Rapid Visco Analyzer and Farinograph were used to thoroughly assess the impact of replacing shortening with oleogels on the qualities of cookie dough. The results demonstrated the efficacy of MAG oleogel in replicating the attributes of traditional shortening in cookie doughs, in terms of water absorption, dough consistency, and dough stability. The overall quality of cookies prepared with oleogels was comparable to the ones prepared with shortening. Additionally, the oxidative stability indicated the remarkable advantage of EPHOSO‐based oleogels, which displayed an elevated resistance to oxidative processes compared to its liquid form. Furthermore, cookies prepared with MAG oleogel exhibited prolonged oxidative stability than those prepared with shortening. Overall, the results underscore the potential of EPHOSO oleogels, particularly those incorporated with MAG, could enhance the oxidative stability of cookies without diminishing the physicochemical qualities of the end product.

Viscometry-based prediction of structural properties of high-moisture meat analogues using gelation properties of soy and pea isolate protein blends

In this study, utilizing the gelation properties of a blend containing soy protein isolate (SPI), pea protein isolate (PPI), and corn starch (CS), we introduced a novel approach to predict the structural attributes of high-moisture meat analogues (HMMA). By leveraging the “Rapid Visco Analyzer 4800″ viscometer, we measured the gelation behavior of SPI and PPI based on temperature profiles, underscoring a method to efficiently forecast fibrous structures and reduce trial errors in complex extrusion processes. As the PPI content increased, we observed a decline in the overall viscosity of the protein mixture, paralleled by a rise in color lightness. Contrary to the sturdy gel network formed by SPI, PPI showcased weaker particle bonds, indicating a structural vulnerability. In line with this, the texture of HMMA diminished as PPI content escalated. The secondary protein structure in both protein gels and HMMA revealed that as PPI content grew, there was a reduction in α-helix and β-sheet structures while random coil structures increased. The molecular strength of the protein gel waned with higher PPI content. Similarly, in HMMA, elevated PPI levels corresponded to fewer protein interactions. The study demonstrates that HMMA's textural properties can be effectively predicted by understanding the gelation characteristics of the SPI-PPI blend, highlighting the need for further research to refine prediction models that incorporate the complexities of molecular interactions in varying processing conditions.

Processing, composition, and technological properties of decorticated, sprouted, and extruded pearl millet (Pennisetum glaucum (L.) R. Br.) flours

AbstractPearl millet (Pennisetum glaucum (L.) R. Br.) is a gluten‐free cereal with potential use in food security and human nutrition; however, it is still relatively unknown by the food industry and by most consumers. In order to evaluate the impact of processing on the nutritional and technological characteristics of pearl millet flours, three different processing methods (decortication, sprouting, and extrusion) were studied. The effects of processing methods on the particle size distribution, proximate composition, mineral content, bulk density, water absorption index, water solubility index (WSI), and pasting properties (rapid visco analyzer) on the flours were evaluated and compared with whole raw flour. The whole raw flour showed particles size of 355 μm, 62.5% carbohydrate, 12.0% protein, 5.6% lipid, 8.2% dietary fiber, and 1.7% ash. Decorticated flour presented decrease in mineral, dietary fiber, and protein content. The extruded flour presented the highest WSI and the lowest lipid content and paste viscosity, whereas sprouted flour showed low setback, paste viscosity, phytate content, and high protein and dietary fiber content. Decorticated and sprouted flour presented the highest luminosity, whereas extruded flours the smallest L*. The increasing color difference (ΔE*) between raw pearl millet and processed flours was sprouted < decorticated < extruded. The production of millet flour should be encouraged for various food applications, especially in Brazil, which has a large cultivated area of this cereal used only for animal feed and an expanding gluten‐free market.Practical applicationsThe impact of pre‐processing methods on millet grains drives its application in the food industry. All processed flours have the potential to be used as a gluten‐free ingredient for celiacs, people with non‐celiac gluten sensitivity, and for food‐style adepts. The extruded flour has the potential to be used in the development of soups, powder drink, snacks, and breakfast cereal, whereas the sprouted flour can be used in frozen and bakery products. The decorticated flour could be explored as a substitute in different food preparations, such as biscuits, pastas, and breads.

Screening on halal gelatin extraction from spotted oceanic triggerfish (Chanthidermis maculata) skin using response surface methodology

Spotted oceanic triggerfish fish is one type of fish that has the potential to be a source of halal gelatin. Almost all parts of his body can become gelatin. In the process of processing the fish, many parts are wasted such as skin. Though this skin can be used for gelatin extract. From the results of the study, gelatin yield ranged from 2.7 – 9.3% with an average value of 5.50%. This gelatin has a viscosity value ranging from 6.21 – 7.57 cP which was analyzed using the Rapid Visco Analyzer (RVA) instrument and gel strength analysis using a Texture Analyzer and found results of 80.33 – 97.67 g / cm2. Based on the probability value < 0.05 yield, viscosity, and gel strength of gelatin, it is known that there are several independent variables that have a real effect on yield, namely variables B (concentration of H2SO4), D (soaking duration), F (ratio of water/extraction skin) and G (extraction temperature). In viscosity, the influential variables are C (citric acid concentration), D (soaking duration), E (soaking water/skin ratio) and G (extraction temperature). While on gel strength, the influential variables are A (NaOH concentration) and G (extraction temperature). The influence of factors on response can be sorted sequentially, namely the order in yield is G>F>B>D>A>H>C>E, in viscosity is C>E>D>G>H>A>B>F and in gel strength is G>A>E>H>B>F>C>D. This indicates that the G factor (extraction temperature) was selected as the most important factor, and the 2nd and 3rd most important factors can be selected from A (NaOH concentration), B (H 2SO4 concentration), D (extraction duration) and E (soaking water/skin ratio), and H (extraction duration).

Effect of hawthorn polyphenol extracts on the physicochemical properties and digestibility of corn starch.

To investigate the effect of hawthorn polyphenols on the physicochemical properties and digestibility of corn starch, different proportions (1%, 2%, 3%, and 4% [w/w]) of hawthorn polyphenol extracts (HPEs) were mixed with corn starch, and their physicochemical properties and digestive properties were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Rapid Visco Analysis, differential scanning calorimetry, and in vitro/in vivo analysis. Results indicated that small V-type crystal starch tended to be formed in the samples, and the addition of HPEs reduced the viscosity, prolonged the gelatinization temperature of corn starch, and increased the proportion of slowly digestible starch and resistant starch of the corn starch, which accounted for 36.32%±1.05% and 33.32%±4.07%, respectively. Compared with the raw corn starch, the postprandial blood glucose of mice that were administered the hawthorn polyphenols decreased significantly: the blood glucose peak (30min) decreased from 14.30±1.52 to 11.77±1.21mmol/L. Our study might provide some basic theoretical support for the application of hawthorn polyphenols in healthy starchy food processing.

Lactose-6-phosphate as an alternative to disodium phosphate in the production of processed cheese food

Processed cheese food (PCF) is a dairy product prepared by blending dairy ingredients with nondairy ingredients and heating the blend with agitation to produce a homogeneous product with an extended shelf life. Emulsifying salts (ES), such as disodium phosphate (DSP) and trisodium citrate, have a critical effect on the emulsification characteristics of casein by sequestering the calcium from the calcium-paracaseinate phosphate complex in natural cheese. Lactose-6-phosphate (LP) is an organic compound produced from lactose that has the potential to function as ES. Lactose-6-phosphate is not approved for use as a substitute for ES in the large-scale production of PC. The objective of this study was to produce PCF with LP instead of DSP. Lactose-6-phosphate was prepared by mixing 1 mol of α-lactose with 0.5 mol of sodium cyclo-triphosphate. The pH of recombined solutions was adjusted using sodium hydroxide to get a pH of 12 to obtain 60.74% LP. The solution was stirred for 3 d at room temperature and then concentrated to 52% total solids (TS). The ingredients in the PCF formulations were Cheddar cheese, butter, water, milk permeate powder, and LP (at a ratio of 2.0, 2.4, 2.8, 3.2, 4.0, 5.0, and 6.0%) were formulated to contain 17.0% protein, 25.0% fat, 44.0% moisture, and 2.0% salt. Processed cheese food made with 2.0% DSP was also produced as a control. The PCF was prepared by mixing all ingredients in a Kitchen Aid stand mixer to make a homogeneous paste. A 25-g sample of the mixture was cooked in the rapid visco analyzer (Perten RVA 4500, Macquarie Park, Australia) for 3 min at 95°C at 1,000 rpm for the first 2 min and 160 rpm for the last minute. The PCF was then transferred into molds and refrigerated till further analyses. The PCF was analyzed for moisture, pH, end apparent cooked viscosity, hardness, melted diameter, and melting temperature. The experiment was repeated 3 times using different batches of LP. The moisture of PCF ranged from 42.3% to 44.0% with a pH of 5.6 to 5.8. The end apparent cooked viscosity increased from 818.0 to 2,060.0 cP as the level of LP raised from 0.63% to 1.90%, whereas it was 660.0 cP in control. The hardness of PCF made with LP elevated from 61.9 to 110.1g as the level of LP increased; however, it was 85.6 g in control. The melted diameter decreased from 43 mm in control to 29 mm in 1.90% LP, while the melting temperature of PCF increased from 37.7°C in control to 59.0°C in 1.90% LP. We conclude that LP can be used as a substitute for DSP in PCF manufacture and has more capacity than DSP.

Effect of different proportions of glycerol and D-mannitol as plasticizer on the properties of extruded corn starch.

In this study, thermoplastic starch (TPS) was prepared by melt extrusion process, in which glycerol and/or D-mannitol were used as plasticizers, and the effect of different glycerol/D-mannitol ratios (4:0, 3:1, 2:2, 1:3, and 0:4) on the physicochemical properties of the extruded starch samples was investigated. The short-range molecular order, crystallization, gelatinization, thermal stability, and thermal properties of the TPS samples were analyzed through attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), rapid visco analysis (RVA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results showed that the crystallinity and short-range molecular order of the TPS samples increased with increasing glycerol content. Conversely, the water absorption index (WAI) and water solubility index (WSI) of the TPS samples decreased with increasing glycerol content. In addition, the TPS samples with higher glycerol content exhibited higher gel and thermal stabilities. This study provides a theoretical basis for starch extrusion and plasticization in the preparation of TPS-based materials with specific properties.

The RING-Type Domain-Containing Protein GNL44 Is Essential for Grain Size and Quality in Rice (Oryza sativa L.).

Grain size in rice (Oryza sativa L.) shapes yield and quality, but the underlying molecular mechanism is not fully understood. We functionally characterized GRAIN NUMBER AND LARGE GRAIN SIZE 44 (GNL44), encoding a RING-type protein that localizes to the cytoplasm. The gnl44 mutant has fewer but enlarged grains compared to the wild type. GNL44 is mainly expressed in panicles and developing grains. Grain chalkiness was higher in the gnl44 mutant than in the wild type, short-chain amylopectin content was lower, middle-chain amylopectin content was higher, and appearance quality was worse. The amylose content and gel consistency of gnl44 were lower, and protein content was higher compared to the wild type. Rapid Visco Analyzer results showed that the texture of cooked gnl44 rice changed, and that the taste value of gnl44 was lower, making the eating and cooking quality of gnl44 worse than that of the wild type. We used gnl44, qgl3, and gs3 monogenic and two-gene near-isogenic lines to study the effects of different combinations of genes affecting grain size on rice quality-related traits. Our results revealed additive effects for these three genes on grain quality. These findings enrich the genetic resources available for rice breeders.