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Environmental factors influence fungal growth and mycotoxin production in stored grains. However, the concentrations of free mycotoxins and their conjugates and how they are impacted by different interacting environment conditions have not been previously examined. The objectives of this study were to examine the impact of storage conditions (0.93–0.98 aw) and temperature (20–25 °C) on (a) the concentrations of deoxynivalenol and zearalenone and their respective glucosides/conjugates and (b) the concentrations of emerging mycotoxins in both naturally contaminated and irradiated wheat grains inoculated with Fusarium graminearum. Contaminated samples were analysed for multiple mycotoxins using Liquid Chromatography Tandem Mass Spectrometry (LC–MS/MS). Method validation was performed according to the acceptable performance criteria set and updated by the European Commission regulations No. 2021/808/EC. As an important conjugate of deoxynivalenol, the concentrations of deoxynivalenol-3-glucoside were significantly different from its precursor deoxynivalenol at 0.93 aw (22% moisture content- MC) at 25 °C in the naturally contaminated wheat with a ratio proportion of 56:44% respectively. The high concentrations of deoxynivalenol-3-glucoside could be influenced by the wheat's variety and/or harvested season/fungal strain type/location. Zeralenone-14-sulfate concentrations were surprisingly three times higher than Zearalenone in the naturally contaminated wheat at 0.98 aw (26% MC) at both temperatures. Emerging mycotoxins such as moniliformin increased with temperature rise with the highest concentrations at 0.95 aw and 25 °C. These findings highlight the influence and importance of storage aw x temperature conditions on the relative presence of free vs conjugated mycotoxins which can have implications for food safety. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The impact of pulsed light treatment (PLT) on natural microbiota and inoculated microbes such as Salmonella Typhimurium, Bacillus cereus, and Aspergillus flavus on red chilies was investigated. Sequential drying did not completely inactivate the aerobic mesophiles and yeast and mold count. Hence, PLT (0.53–2.59 J cm−2) was employed as a decontamination technology on red chilies. PLT resulted in 8 log reduction of inoculated microorganisms on chilies at 2.59 J cm−2. The microbial inactivation kinetics followed Weibull distribution (R2 > 0.97) with β value of 1.1, 1.2, and 1.5 for S. Typhimurium, B. cereus, and A. flavus, respectively. Changes in structure and composition of cell components were identified by SEM and FTIR analysis. After PLT, phenolics, antioxidants, flavonoids, and capsaicinoids were better retained but a significant change in ascorbic acid and carotenoid's content was observed. Hence, PL can be a potential technology for decontamination of fresh and dried chilies along with maximum retention of bioactives. [ABSTRACT FROM AUTHOR]

Subaerial biofilms (SAB) are intricate microbial communities living on terrestrial surfaces, of interest in a variety of contexts including cultural heritage preservation, microbial ecology, biogeochemical cycling, and biotechnology. Here we propose a mathematical model aimed at better understanding the interplay between cyanobacteria and heterotrophic bacteria, common microbial SAB constituents, and their mutual dependence on local environmental conditions. SABs are modeled as thin mixed biofilm-liquid water layers sitting on stone. A system of ordinary differential equations regulates the dynamics of key SAB components: cyanobacteria, heterotrophs, polysaccharides and decayed biomass, as well as cellular levels of organic carbon, nitrogen and energy. These components are interconnected through a network of energetically dominant metabolic pathways, modeled with limitation terms reflecting the impact of biotic and abiotic factors. Daily cylces of temperature, humidity, and light intensity are considered as input model variables that regulate microbial activity by influencing water availability and metabolic kinetics. Relevant physico-chemical processes, including pH regulation, further contribute to a description of the SAB ecology. Numerical simulations explore the dynamics of SABs in a real-world context, revealing distinct daily activity periods shaped by water activity and light availability, as well as longer time scale survivability conditions. Results also suggest that heterotrophs could play a substantial role in decomposing non-volatile carbon compounds and regulating pH, thus influencing the overall composition and stability of the biofilm. [ABSTRACT FROM AUTHOR]

This research unveiled new insights on the impact of incorporating whey proteins into kefir produced using three different methods. This aims to improve its quality and health benefits, primarily as a result of optimal proliferation of probiotic bacteria. In the initial part of the experiment, samples were prepared using three different methods (methods 1, 2, and 3) to examine the impact of introducing whey protein on bacterial count, the content of L(+)-lactic acid, lactase activity, and the lactic acid and ethanol levels. The methods differed primarily in the sequence of the inoculation milk with probiotic bacteria stage in the production cycle, as well as incubation time and temperature. No significant differences were found in the number of yeasts and bacteria between samples with and without whey proteins. However, it was revealed that the 5% addition of whey proteins enhanced the number of probiotic bacteria in kefir produced with method 2 (from 4.86 to 5.52 log cfu/mL) and method 3 (from 3.68 to 4.01 log cfu/mL). The second part of the research investigated the impact of whey proteins on firmness, consistency, cohesiveness, viscosity, color, and water activity of kefir. This part focused on testing samples with lower whey protein contents (1 and 3%, w/v). We found that the addition of 1% and 3% whey proteins resulted in decreased firmness, consistency, cohesiveness, and viscosity compared to the control kefir. On the other hand, the addition of 5% whey proteins resulted in increased firmness and consistency compared to the addition of 1% and 3% whey proteins. The addition of whey protein decreased the white index WI of the kefir samples. Overall, our results revealed that incorporating whey protein concentrate (WPC) in the production of probiotic kefir can enhance its health benefits while maintaining its rheological properties and overall quality. [ABSTRACT FROM AUTHOR]

Apple and ginger mixed pomace is a by-product that can be valorized by drying. In this study, mixed pomace was subjected to hot-air drying (HAD) at 45, 62, and 70 °C and stepwise at 45 °C followed by at 62 °C or the reverse, at 62 °C followed by at 45 °C (2.5 mm layer), and microwave drying (MWD) at 100, 180, and 300 W (2.5 mm and 1.5 mm layers) and stepwise at 100 W followed by at 300 W (2.5 mm layer). The results show that the Crank model well fitted the HAD kinetics, with a water effective diffusivity (Deff) of 2.28 ± 0.06 × 10−10–4.83 ± 0.16 × 10−10 m2/s and energy of activation of 23.9 kJ/mol. The step approach of drying at 45 °C followed by at 62 °C resulted in a higher Deff than the reverse approach (drying at 62 °C followed by at 45 °C). The Midilli et al. model presented a good fit for the MWD kinetics. The drying time was calculated using these models to achieve 12% moisture content in the pomace and found to be 125.0 ± 9.2–439.5 ± 118.2 min for HAD, and 11.1 ± 0.2–61.5 ± 6.0 min for MWD. The specific energy required was 410.78 ± 6.30–763.79 ± 205.4 kWh/kg and 1.32 ± 0.01–2.26 ± 0.05 kWh/kg, respectively. MWD at 180 W preserved the total phenolic content and the antioxidant activity (ABTS, DPPH) better than HAD at 62 °C. The former technology also preserved the pomace color well, with a low color difference, ΔE, of 7.39 ± 1.1. Therefore, MWD is more promising than HAD to dry apple and ginger pomace, reducing the environmental impact of the drying process due to its lower energy consumption, shorter drying time, and better quality. The dried product could be converted into apple and ginger pomace flour to be used as a novel food ingredient. [ABSTRACT FROM AUTHOR]

Betacyclodextrin (β-CD)-assisted extracts of green rooibos displayed elevated polyphenolic content and antioxidant activity compared with aqueous extracts. This study aimed to analyse the physicochemical properties of aqueous green rooibos and 15 Mm β-CD at 40 °C for 60 min. Sorption isotherms and colour (L*a*b*C*) were evaluated. Thermogravimetric analysis and Fourier transform infrared were conducted to verify encapsulation. Sorption isotherm studies revealed that β-CD reduced water uptake, resulting in a reduction in the monolayer value of GRE (7.90) to 6.40 for β-GRE. Betacyclodextrin contributed to increased lightness (L*) and decreased redness (a*) of green rooibos. However, storing extracts at varied water activity resulted in a reduction in L* and chroma (C*), with a higher reduction observed for GRE than β-GRE. Thermogravimetric analysis revealed that GRE degraded at 180 °C, followed by β-GRE at 260 °C and β-CD at 340–375 °C. Betacyclodextrin increased the thermal stability of green rooibos; as a result, β-GRE displayed a superposition of GRE and β-CD in its thermogram, confirming the formation of inclusion complexes. Fourier transform infrared spectra indicated the disappearance or shifting of characteristic peaks, with the formation of hydrogen bonds between GRE and β-CD at the 1255 cm−1 band depicting C–O stretching of carboxylic acid. [ABSTRACT FROM AUTHOR]

The development of aqueous Zn‐based energy storage systems is plagued by poor cyclability and limited operating temperatures caused by Zn anode issues and highly active water. Herein, a frost‐tolerant hydrogel electrolyte (PABCHE) promoted by hydroxyl‐rich β‐cyclodextrin (β‐CD) and zwitterionic betaine (BA) additives is fabricated in situ to protect Zn anodes and enhance low‐temperature adaptability. Both additives synergistically disrupt the hydrogen‐bonding network between water molecules to remarkably reduce the freezing point of PABCHE and alleviate water‐associated side effects. Zwitterionic BA constructs ion‐migration channels and regulate Zn2+ solvation structure, promoting uniform and rapid transport of Zn2+. Additionally, PABCHE renders the Zn2+ homoepitaxially depositing along the (002) plane to achieve dendrite‐free Zn anodes. As a result, versatile PABCHE enables Zn//Zn cells to cycle stably for 1100 and 3600 h at 20 and −20 °C, respectively. Furthermore, the Zn‐ion hybrid capacitors optimized by PABCHE deliver favorable cyclability over 30000 cycles at 20 °C (with a capacity retention of 81.8%) and −20 °C (with a capacity retention of 84.2%). Additionally, PABCHE can be applied as a flexible strain sensor for real‐time monitoring of physiological activities. This work offers valuable insights for developing antifreeze hydrogel electrolytes toward applications of dendrite‐free low‐temperature Zn‐based devices and strain sensors. [ABSTRACT FROM AUTHOR]

Suppressing the water activity is challenging to achieve high‐performing aqueous zinc ion batteries (AZIBs), especially for its practical climate adaptability. Reconstructing the H‐bond network and repealing the solvation water can effectively reinforce the covalency inside water molecular. Here, a hydrogel electrolyte formula utilizing ClO4− anions and hydrophilic ─NH2 on polyacrylamide chains is shown to bond with water molecules, while the zincophilic glucose preferentially regulate Zn2+ solvation. The multifunctional hydrogel structure can effectively disrupt the intrinsic H‐bond network and inhibit the interface side‐reactions induced by active water. Finally, the delayed freezing point and expanded voltage stability window are realized, which promotes the ZIBs steady operate in a wide temperature range. When operating at 70 and −30 ˚C, the Zn//NVO battery achieves high specific capacity of 488 and 254 mAh g−1, respectively, surpassing most of the previously reported results. Remarkably, the pouch battery delivers the state‐of‐the‐art specific capacity of 438.1 mAh g−1 and realizes a capacity retention of 76.3% after 400 cycles at 200 mA g−1. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of different ventilation systems in two aging cells. One cell featured transverse airflow starting from the top, while the other had a dual-flow system with vertical air motion from top to bottom and vice versa. In addition to monitoring weight loss during aging, chemical and physical analyses were conducted on various salamis to assess the influence of ventilation both between the two aging cells and among different positions of the salamis within the same cell. It was found that the dual-evaporator (DEV) cell behaved better than transverse flow (TFL) cell. [ABSTRACT FROM AUTHOR]

Highlights: Total phenolic contents and total flavonoid contents from Averrhoa bilimbi showed correlation to antioxidant properties. Freeze drying preserved the antioxidative properties of fruit compared to oven drying. Low moisture food product from A. bilimbi with ranging Aw (0.48 to 0.51) and moisture content (15.56 to 24.81%). A. bilimbi exhibited different microstructural and functional group after exposed to different drying method. The use of natural-based ingredients for nutricosmetics, boasting remarkable phytochemical compounds and antioxidant properties sourced from underutilized fruits, has also gained widespread recognition. The present study was conducted to preserve Averrhoa bilimbi using emerging technology of freeze drying. Low moisture food ingredient in powder form was produced from A. bilimbi fruit. The freeze dried of A. bilimbi was compared with classic drying method such as oven drying in term of moisture content, water activity, total phenolic content, total flavonoid content, DPPH, and ABTS scavenging activities. The result showed that freeze dried A. bilimbi exhibited highest total phenolic content (18.59 ± 3.39 µg GAE /mg), total flavonoid content (0.010 ± 0.000 µg RE /mg), the strongest DPPH (9.25 ± 0.43 mg/mL), ABTS (5.88 ± 0.26 mg/mL) scavenging activities, compared to oven drying technique. The moisture content of freeze dried A. bilimbi (24.81 ± 4.08%) exhibited higher compared to oven dried of A. bilimbi. The freeze dried A. bilimbi (0.48 ± 0.00 aw) demonstrated higher water activity compared to oven drying technique. Microstructure of freeze dried sample was different from oven dried sample. Oven dried sample microstructure experience a serious damage. The chemical screening and identification was conducted using gas chromatography (GC-MS) and high-performance liquid chromatography tandem mass spectrometry of triple quadrupole (HP LCMS-MS QTOF). The freeze drying technology presents a promising result of emerging technology for preserving fruit products. Hence, this emerging drying method presents a good scope for application in the food and cosmetic industry, with good commercial value. [ABSTRACT FROM AUTHOR]

Oral non-tobacco nicotine products have gained enormous popularity in recent years. The countries of the Eurasian Economic Union also produce and sell this type of innovative but poorly studied goods. As a result, the safety profile and quality of such products as nicotine poaches require urgent comprehensive research. This study featured the changes in quality of nicotine poaches during storage, i.e. nicotine content, water activity, and microbiological index. The research featured nicotine poaches of several popular brands. The authors used standard research methods; the experiments were performed in the laboratory for chemistry and quality control, Institute of Tobacco, Makhorka, and Tobacco Products, Krasnodar, and at the Department of Bioorganic Chemistry and Technical Microbiology, Kuban State Technological University, Krasnodar. The water activity was 0.8911–0.9502 Aw at the initial stage and remained stable in most samples even after six months of storage. Velo Freeze was the only brand to show significant variations in water activity. The nicotine content was 10.115–12.950 mg/g at the initial stage. Only four samples maintained the initial values after six months of storage. The fluctuations of nicotine content were also mentioned by the manufacturer. The microbiological profile remained stable during the six months of storage and met the requirements for similar products, i.e., chewing gum and unglazed caramel. The project needs further research because the qualitative characteristics of nicotine poaches provided rather unambiguous results. Our study will help develop state standards for oral nicotine products. The results obtained will be used to formulate proposals to the organizations responsible for the future Technical Regulations of the Eurasian Economic Union for nicotine products.

The drying and storage process in jelly candy present a significant challenges due to their impact on stability. This study investigates the drying kinetics and moisture sorption isotherms of jelly candy. The aim of the study focuses on comparing the effectiveness of conventional models (Courie-GAB-Peleg) and artificial neural networks (ANN) in analyzing the sorption behaviour of jelly candy, specifically when corn stract was added. In addition, the drying characteristics, shrinkage, and storage recommendations of jelly candies were also identified. The static gravimetric method uses a saturated solution of sulfuric acid with 13 (thirteen) different concentrations to condition the water activity (aw) in the range of 0.06–0.89 (25–35 °C). In addition, the oven drying processed at a temperature of 40–60 °C with an air speed of 3.6 m/s. The study results show that the final equilibrium moisture content (EMC) of drying has a range of 19.74%w.b-22.02%w.b, and the highest drying rate is 0.11%w.b/min-0.27%w.b/min. At the end of dryng, shrinkage of jelly candy is 22-33% compared to initial conditions. Based on the model accuracy test, it shows that the Peleg model was identified as the best model. The correlation between drying kinetic and moisture sorption was explained with storage recommendations and its recommendation for good jelly candy storage is 24.19%w.b. These storage recommendations were used to determine the appropriate stop of the drying process to minimize drying time. [ABSTRACT FROM AUTHOR]

Rice bran, a byproduct of rice processing, holds great nutritional value. However, its application in the food industry is greatly restricted due to its high susceptibility to rancidity and spoilage during storage. Currently, it is primarily used as animal feed with low added value. The presence of lipase and lipoxygenase is the major cause of rapid rancidity of rice bran, and other factors such as water activity, microorganisms and phenolic substances also affect the rancidity reaction. Stabilization treatment of rice bran is a key prerequisite to achieving high-value utilization of the product. This paper provides an overview of the rancidity mechanism of rice bran, the common methods for stabilizing rice bran and their impact on its quality and nutritional characteristics, with a view to providing guidance and reference for the research and development of rice bran as a food-grade raw material.

Aspergillus westerdijkiae is a major producer of ochratoxin A (OTA), a highly toxic and carcinogenic mycotoxin found in various food and feed products. A. westerdijkiae produces excessive amount of OTA under various water activity (aw) conditions that occur during food and feed storage. The biosynthetic gene clusters associated with OTA production include OTAbZIP, which plays a key role in controlling mycotoxin production in response to environmental conditions. This study explored the regulation of OTA biosynthesis in A. westerdijkiae fc-1, focusing on the OTAbZIP gene’s influence under aw stress. The mycelium growth of A. westerdijkiae fc-1 wild type and OTAbZIP mutant strains increased by 40.7% and 50.5% under high water activity (0.96 aw) respectively, at 6 days post-inoculation (dpi), indicating a stress on A. westerdijkiae fc-1. While OTAbZIP mutant did not produce OTA under both high and moderate aW conditions. The wild type produced OTA and OTA biosynthetic gene expression levels were downregulated under high (0.96 aw) and moderate (0.91 aw) water activity. The expression level of hog1 gene in OTAbZIP mutant was significantly lower than in the wild type. Pathogenicity tests revealed that deletion of OTAbZIP did not significantly affect disease infection. This study shows that deleting OTAbZIP gene greatly reduces OTA production, affecting the strain’s adaptability to water activity stress.

The aim of this study was to apply osmotic dehydration (OD) to produce minimally processed chayote (Sechium edule (Jacq.) Swartz) slices. Thus, the effect of osmotic solution concentration, temperature, processing time, and vacuum pulse application on mass transfer during osmotic dehydration of the fruit was evaluated. The kinetics of water loss (WL), solids gain (SG), and water activity (aw) were obtained using sucrose solutions with concentrations of 40, 50 and 60 °Bx at 25, 35 and 45 °C. Osmotic solution concentration, temperature, and processing time had a greater influence than vacuum pulse application on WL and SG. The temperature showed an Arrhenius-type dependence on effective diffusivity. The osmodehydrated chayote had lower aw (up to 0.846), higher total soluble solids (TSS) content (up to 31.9 °Bx) and purer and more intense color (up to 18.75 in chroma) compared to fresh chayote. These findings suggest that OD allows for the production of minimally processed chayote that could be included in quick-cook products, such as salads or soup mixes. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We treated dry black bean dreg fermentation products with radio-frequency (RF) waves. With RF treatment (RF output power of 3 kW and electrode gap of 12 cm), a sample was dried within 1 h, which would take 10 h to dry via hot-air drying at 60 °C (sample weight reduction from 100 to 28.2 g). RF treatment thus accelerated fermented black bean dreg drying approximately 10-fold. The fermented black bean dregs were dried for 60 min at a fixed RF output power of 3 kW with different electrode gaps (12, 16, and 20 cm). Samples treated with electrode gaps of 12 and 16 cm were completely dried. When the fermented black bean dregs were dried for 60 min with an RF output power of 3 kW with a 16 cm electrode gap, their water activity decreased from 0.98 to 0.65. Colorimetric analysis showed that the sample color darkened significantly (ΔE = 5.73 ± 2.71), whereas its solubility (28.8 ± 0.1%) and antioxidant capacity (EC50 = 51.7 ± 0.7 mg/mL) increased. In addition, deglycosylated isoflavone daidzein content significantly increased, whereas that of the glycosylated isoflavone genistin decreased. These results reveal that RF application can efficiently dry fermented black bean dregs. [ABSTRACT FROM AUTHOR]

Copyright of Knowledge: International Journal is the property of Institute for Knowledge Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the impacts of a drying process under low temperature and reduced pressure (non-thermal drying) on the final dehydrated products characteristics. This process is based on the retention of water on molecular sieves with a good selectivity against these molecules. In this study, drying experiments of 7mm thick apple slices (AS) were performed and compared to apple slices pretreated by freezing. It was concluded that the dehydrated apple slices were depleted of the maximum amount of water after 12 hours of drying, with a final water content equal to 12 ± 1.75%, whereas after freezing pretreatment, a decrease in drying time to 7 hours was observed, as well as a decrease in water content to 10 ± 0.5%. This explains the effect of freezing pretreatment on accelerating water transfer. In addition, a convective drying was performed on the apple slices at 60°C, which allows comparison with the slices dried by our non-thermal drying process. In order to characterize the obtained fruits, characteristic analyses such as water activity (Aw), color, texture (hardness), and dimensions (diameter and thickness) were performed before and after each drying experiment. Thus, continuous measurements of temperature, humidity, and pressure, within the enclosure, were determined during the experiments using a wireless sensor system controlled by a programming Arduino. Finally, mathematical modeling by various models (Newton, Page, Midilli, etc.) was performed to determine the most suitable model describing the non-thermal and convective drying of apple slices. [ABSTRACT FROM AUTHOR]

Aspergillus westerdijkiae is a major producer of ochratoxin A (OTA), a highly toxic and carcinogenic mycotoxin found in various food and feed products. A. westerdijkiae produces excessive amount of OTA under various water activity (aw) conditions that occur during food and feed storage. The biosynthetic gene clusters associated with OTA production include OTAbZIP, which plays a key role in controlling mycotoxin production in response to environmental conditions. This study explored the regulation of OTA biosynthesis in A. westerdijkiae fc-1, focusing on the OTAbZIP gene’s influence under aw stress. The mycelium growth of A. westerdijkiae fc-1 wild type and OTAbZIP mutant strains increased by 40.7% and 50.5% under high water activity (0.96 aw) respectively, at 6 days post-inoculation (dpi), indicating a stress on A. westerdijkiae fc-1. While OTAbZIP mutant did not produce OTA under both high and moderate aW conditions. The wild type produced OTA and OTA biosynthetic gene expression levels were downregulated under high (0.96 aw) and moderate (0.91 aw) water activity. The expression level of hog1 gene in OTAbZIP mutant was significantly lower than in the wild type. Pathogenicity tests revealed that deletion of OTAbZIP did not significantly affect disease infection. This study shows that deleting OTAbZIP gene greatly reduces OTA production, affecting the strain’s adaptability to water activity stress. [ABSTRACT FROM AUTHOR]

Unique worldwide, nitrate/iodine deposits (NIDs) are located along a 700 km geological belt in the Atacama Desert, Chile. They serve as the primary source of mineral ores for the extraction of iodine, sodium, and potassium nitrates. NIDs have been relatively underexplored from a biological perspective. To address this, we collected sixteen soil samples from abandoned mines in Oficinas Pissis and Savona for chemical, mineralogical, and metagenomic analyses. The soils primarily consisted of halite and darapskite, with only one sample being predominantly composed of thenardite. Deliquescence and water activity measurements yielded values ranging from 0.02% to 0.40% and 0.47 to 0.62, respectively. To investigate the presence, identification, relative abundance, and diversity of microbial life in NID soils, we employed MiSeq high-throughput sequencing and bioinformatic tools. The dominant phyla observed were Firmicutes and Proteobacteria, with Actinobacteria and Cyanobacteria being predominant in two soil samples. Furthermore, we detected nitrate/perchlorate-reducing bacterial activity in enriched cultures from the soil samples. This study sheds light on the resilience of microbial life in the Atacama Desert NIDs, providing compelling evidence for its existence and offering insight into factors that could facilitate it within this unique environment. [ABSTRACT FROM AUTHOR]

The aim of this study was to apply osmotic dehydration (OD) to produce minimally processed chayote (Sechium edule (Jacq.) Swartz) slices. Thus, the effect of osmotic solution concentration, temperature, processing time, and vacuum pulse application on mass transfer during osmotic dehydration of the fruit was evaluated. The kinetics of water loss (WL), solids gain (SG), and water activity (aw) were obtained using sucrose solutions with concentrations of 40, 50 and 60 °Bx at 25, 35 and 45 °C. Osmotic solution concentration, temperature, and processing time had a greater influence than vacuum pulse application on WL and SG. The temperature showed an Arrhenius-type dependence on effective diffusivity. The osmodehydrated chayote had lower aw (up to 0.846), higher total soluble solids (TSS) content (up to 31.9 °Bx) and purer and more intense color (up to 18.75 in chroma) compared to fresh chayote. These findings suggest that OD allows for the production of minimally processed chayote that could be included in quick-cook products, such as salads or soup mixes.

The study is aimed at assessing the sorption properties of dried hemp (Cannabis sativa L.), which determines the storage stability of the raw material. The statistical and desiccator method was used, with the BET equation used to mathematically interpret the course of the water vapor sorption isotherms. Based on the study, it was found that product IV had the best sorption properties - dried hemp with the lowest degree of fragmentation and non-decarboxylated. Product IV was characterized by the highest water absorption capacity and the highest values ​​of the BET equation parameters (6.13 g/100 g d. m. for the capacity of the monomolecular layer and 215.3 m2/g for the specific sorption surface).

ABSTRACT: Whey butter is the result of the rational use of the whey component, which is cream whey. It is an alternative to milk cream butter. The aim of the presented study was to analyze the effect of storage conditions on water thermodynamics and cholesterol oxidation products as reliable markers of quality and safety. After 4 mo of storage, the water loss (at 3°C and 13°C) and water activity in whey butter (only at 13°C) were reduced. Three-factorial ANOVA showed that the value of water activity was independent of the type of butter in interaction with the storage temperature. The duration of the translational movement of water molecules from the inside of whey butter was definitely longer than in butter and shortened with storage time. This was in contrast to butter. For whey butter stored at 13°C, the kinetics of the movement of water molecules was at the highest speed. In the case of whey butter and butter, the higher storage temperature almost doubled the gloss. Increasing the temperature to 13°C resulted in different yellowness index, chroma, and browning index between whey butter and butter. There were no statistically significant differences in the percentage of fatty acids and triacylglycerols in whey butter and milk cream butter during storage. In whey butter, compared with butter, the cholesterol content was higher, but the amount of cholesterol oxidation products was smaller. However, in whey butter, these amounts increased significantly. The presence of epoxides and their transformation products (i.e., triol cholesterol) was found in storage whey butter.

Abstract The Mars Sample Return mission intends to retrieve a sealed collection of rocks, regolith, and atmosphere sampled from Jezero Crater, Mars, by the NASA Perseverance rover mission. For all life-related research, it is necessary to evaluate water availability in the samples and on Mars. Within the first Martian year, Perseverance has acquired an estimated total mass of 355 g of rocks and regolith, and 38 μmoles of Martian atmospheric gas. Using in-situ observations acquired by the Perseverance rover, we show that the present-day environmental conditions at Jezero allow for the hydration of sulfates, chlorides, and perchlorates and the occasional formation of frost as well as a diurnal atmospheric-surface water exchange of 0.5–10 g water per m2 (assuming a well-mixed atmosphere). At night, when the temperature drops below 190 K, the surface water activity can exceed 0.5, the lowest limit for cell reproduction. During the day, when the temperature is above the cell replication limit of 245 K, water activity is less than 0.02. The environmental conditions at the surface of Jezero Crater, where these samples were acquired, are incompatible with the cell replication limits currently known on Earth.

This study aims to determine the modelling of the sorption phenomenon, which is influenced by temperature and relative humidity in Barlin bananas. Modification of GAB to obtain new equations for determining spreading pressure and Gibbs free energy values was evaluated in this study. In addition, the characteristics of bananas (surface topography, functional groups, and crystal phase) were identified. Treatment incubation temperatures were 5–25 °C using the static gravimetric method. Equilibrium moisture content was directly proportional to the temperature and water activity increased with water content of 11.52–51.36%db (adsorption) and 25.59–97.01%db (desorption). Based on the BET classification, the sorption curve of Barlin banana pieces forms a type II. Then, the Peleg model became the best model for predicting desorption and adsorption phenomena in Barlin bananas with values of R2 > 0.9900, P < 0.05, and RMSE < 0.01. The process of identifying the new equation from the modified GAB equation indicates that the values of spreading pressure and Gibbs free energy are 0.93–1.68 J/m2 and 0.12–52.49 J/mol, respectively. FE-SEM determination shows swelling on the material's surface, allowing surface desorption and adsorption. Meanwhile, FTIR analysis results show the valley point at 3273.16, indicated as an OH bond, and 2926.59, indicated as a C–H bond. Then, XRD shows that the crystallinity level was 39.48%, and the peak point is 2θ = 17.08º, which generally occurs in starch. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Whey butter is the result of the rational use of the whey component, which is cream whey. It is an alternative to milk cream butter. The aim of the presented study was to analyze the effect of storage conditions on water thermodynamics and cholesterol oxidation products as reliable markers of quality and safety. After 4 mo of storage, the water loss (at 3°C and 13°C) and water activity in whey butter (only at 13°C) were reduced. Three-factorial ANOVA showed that the value of water activity was independent of the type of butter in interaction with the storage temperature. The duration of the translational movement of water molecules from the inside of whey butter was definitely longer than in butter and shortened with storage time. This was in contrast to butter. For whey butter stored at 13°C, the kinetics of the movement of water molecules was at the highest speed. In the case of whey butter and butter, the higher storage temperature almost doubled the gloss. Increasing the temperature to 13°C resulted in different yellowness index, chroma, and browning index between whey butter and butter. There were no statistically significant differences in the percentage of fatty acids and triacylglycerols in whey butter and milk cream butter during storage. In whey butter, compared with butter, the cholesterol content was higher, but the amount of cholesterol oxidation products was smaller. However, in whey butter, these amounts increased significantly. The presence of epoxides and their transformation products (i.e., triol cholesterol) was found in storage whey butter. [ABSTRACT FROM AUTHOR]

The Mars Sample Return mission intends to retrieve a sealed collection of rocks, regolith, and atmosphere sampled from Jezero Crater, Mars, by the NASA Perseverance rover mission. For all life-related research, it is necessary to evaluate water availability in the samples and on Mars. Within the first Martian year, Perseverance has acquired an estimated total mass of 355 g of rocks and regolith, and 38 μmoles of Martian atmospheric gas. Using in-situ observations acquired by the Perseverance rover, we show that the present-day environmental conditions at Jezero allow for the hydration of sulfates, chlorides, and perchlorates and the occasional formation of frost as well as a diurnal atmospheric-surface water exchange of 0.5–10 g water per m2 (assuming a well-mixed atmosphere). At night, when the temperature drops below 190 K, the surface water activity can exceed 0.5, the lowest limit for cell reproduction. During the day, when the temperature is above the cell replication limit of 245 K, water activity is less than 0.02. The environmental conditions at the surface of Jezero Crater, where these samples were acquired, are incompatible with the cell replication limits currently known on Earth. [ABSTRACT FROM AUTHOR]

Salting influences microbial growth, enzymatic activity, and biochemical reactions during ripening, thus contributing to the final quality of cheese. The aim of this study was to evaluate the influence of different salting methods (dry salting at 12, 24, and 48 h; salting in brine; and salting of partially drained curd, before moulding) on the chemical (moisture and salt content), physicochemical (pH, titratable acidity, and water activity), and sensory characteristics (texture profile analysis, colour, and sensory attributes) of industrial blue-veined cheese. Dry-salted cheeses had lower moisture content and water activity, and higher salt/moisture content and acidity than those salted in brine and in the partially drained curd. Dry-salted cheeses were also characterised by higher values for hardness, fracturability, and instrumental gumminess. Dry-salted cheeses showed differences only in the red/green colour component (a*), with the cheeses salted in the partially drained curd being less greenish. All cheeses scored high (around 7) in the tasters' overall impression, with the dry-salted cheeses at 12 and 24 h showing optimal growth and distribution of mould, as well as better flavour and texture. [ABSTRACT FROM AUTHOR]

This work proposes a novel drying method suitable for probiotic bacteria, called flash freeze-drying (FFD), which consists of a cyclic variation in pressure (up-down) in a very short time and is applied during primary drying. The effects of three FFD temperatures (−25 °C, −15 °C, and −3 °C) on the bacterial survival and water activity of Lactobacillus acidophilus LA5 (LA), previously microencapsulated with calcium alginate and chitosan, were evaluated. The total process time was 900 min, which is 68.75% less than the usual freeze-drying (FD) time of 2880 min. After FFD, LA treated at −25 °C reached a cell viability of 89.94%, which is 2.74% higher than that obtained by FD, as well as a water activity of 0.0522, which is 55% significantly lower than that observed using FD. Likewise, this freezing temperature showed 64.72% cell viability at the end of storage (28 days/20 °C/34% relative humidity). With the experimental data, a useful mathematical model was developed to obtain the optimal FFD operating parameters to achieve the target water content in the final drying. [ABSTRACT FROM AUTHOR]

Abstract This study aims to investigate the relationship between casein oxidation and moisture status in the presence of milk fat to clarify the role of fat on water in milk powder. The results showed that at the same water activity (aw), the faster oxidation of whole milk powder (WMP) is attributed to the high proportion of free water and immobilized water in them, indicating that the adsorption of milk fat mainly depended on multilayer water and the entrapped water. In the diffusion‐limited reaction, changes in water state affected more than radicals on casein oxidation. Glass transition temperature (Tg) was also affected by the water state of lipid adsorption. At low aw (

Currently, the key trends in the global food market include the rapidly developing functional nutrition industry, which is of great interest to consumers. Inulin is a natural polysaccharide of plant origin, consisting of residues of E-fructofuranose (fructose). The object of the research is inulin extract from Jerusalem artichoke at different humidity levels. It has been established that to intensify the drying process of inulin extract, it is advisable to increase the mass transfer surface, which can be achieved by spraying the initial product, and using volumetric energy supply methods, in particular, radiation energy supply. The important and most energy-intensive stages of drying are carried out in the hygroscopic area of equilibrium humidity of the object of the research, which determines the intensity and mechanism of the dehumidification operation in order to increase the degree of perfection, select rational operating parameters, adapt to the object of the analysis and solve a mathematical model of removal moisture from it. Based on the sorption isotherms and hygroscopic parameters of the inulin extract obtained in preliminary studies, obtained by dehydrating the inulin extract from Jerusalem artichoke (variety «Skorospelka», grown by JSC «Chaganskoe», the bAstrakhan region), a thermodynamic analysis of the process of sorption and desorption was carried out in different ranges of humidity variation. The total binding energy of moisture with the dry residue of inulin and its thermodynamic components were found. The data obtained do not contradict known literature sources and can be recommended when designing processes for removing moisture from inulin extract and designing drying devices.

Salting influences microbial growth, enzymatic activity, and biochemical reactions during ripening, thus contributing to the final quality of cheese. The aim of this study was to evaluate the influence of different salting methods (dry salting at 12, 24, and 48 h; salting in brine; and salting of partially drained curd, before moulding) on the chemical (moisture and salt content), physicochemical (pH, titratable acidity, and water activity), and sensory characteristics (texture profile analysis, colour, and sensory attributes) of industrial blue-veined cheese. Dry-salted cheeses had lower moisture content and water activity, and higher salt/moisture content and acidity than those salted in brine and in the partially drained curd. Dry-salted cheeses were also characterised by higher values for hardness, fracturability, and instrumental gumminess. Dry-salted cheeses showed differences only in the red/green colour component (a*), with the cheeses salted in the partially drained curd being less greenish. All cheeses scored high (around 7) in the tasters’ overall impression, with the dry-salted cheeses at 12 and 24 h showing optimal growth and distribution of mould, as well as better flavour and texture.

Betacyclodextrin (β-CD)-assisted extracts of green rooibos displayed elevated polyphenolic content and antioxidant activity compared with aqueous extracts. This study aimed to analyse the physicochemical properties of aqueous green rooibos and 15 Mm β-CD at 40 °C for 60 min. Sorption isotherms and colour (L*a*b*C*) were evaluated. Thermogravimetric analysis and Fourier transform infrared were conducted to verify encapsulation. Sorption isotherm studies revealed that β-CD reduced water uptake, resulting in a reduction in the monolayer value of GRE (7.90) to 6.40 for β-GRE. Betacyclodextrin contributed to increased lightness (L*) and decreased redness (a*) of green rooibos. However, storing extracts at varied water activity resulted in a reduction in L* and chroma (C*), with a higher reduction observed for GRE than β-GRE. Thermogravimetric analysis revealed that GRE degraded at 180 °C, followed by β-GRE at 260 °C and β-CD at 340–375 °C. Betacyclodextrin increased the thermal stability of green rooibos; as a result, β-GRE displayed a superposition of GRE and β-CD in its thermogram, confirming the formation of inclusion complexes. Fourier transform infrared spectra indicated the disappearance or shifting of characteristic peaks, with the formation of hydrogen bonds between GRE and β-CD at the 1255 cm−1 band depicting C–O stretching of carboxylic acid.

This research unveiled new insights on the impact of incorporating whey proteins into kefir produced using three different methods. This aims to improve its quality and health benefits, primarily as a result of optimal proliferation of probiotic bacteria. In the initial part of the experiment, samples were prepared using three different methods (methods 1, 2, and 3) to examine the impact of introducing whey protein on bacterial count, the content of L(+)-lactic acid, lactase activity, and the lactic acid and ethanol levels. The methods differed primarily in the sequence of the inoculation milk with probiotic bacteria stage in the production cycle, as well as incubation time and temperature. No significant differences were found in the number of yeasts and bacteria between samples with and without whey proteins. However, it was revealed that the 5% addition of whey proteins enhanced the number of probiotic bacteria in kefir produced with method 2 (from 4.86 to 5.52 log cfu/mL) and method 3 (from 3.68 to 4.01 log cfu/mL). The second part of the research investigated the impact of whey proteins on firmness, consistency, cohesiveness, viscosity, color, and water activity of kefir. This part focused on testing samples with lower whey protein contents (1 and 3%, w/v). We found that the addition of 1% and 3% whey proteins resulted in decreased firmness, consistency, cohesiveness, and viscosity compared to the control kefir. On the other hand, the addition of 5% whey proteins resulted in increased firmness and consistency compared to the addition of 1% and 3% whey proteins. The addition of whey protein decreased the white index WI of the kefir samples. Overall, our results revealed that incorporating whey protein concentrate (WPC) in the production of probiotic kefir can enhance its health benefits while maintaining its rheological properties and overall quality.

The aim of this study was to evaluate the influence of different ventilation systems in two aging cells. One cell featured transverse airflow starting from the top, while the other had a dual-flow system with vertical air motion from top to bottom and vice versa. In addition to monitoring weight loss during aging, chemical and physical analyses were conducted on various salamis to assess the influence of ventilation both between the two aging cells and among different positions of the salamis within the same cell. It was found that the dual-evaporator (DEV) cell behaved better than transverse flow (TFL) cell.

Food is one of the basic needs of human life. With the increasing population, the production and supply of safe and quality foods are critical. Foods can be classified into different categories including low moisture, intermediate moisture, and high moisture content. Historically, low‐moisture foods have been considered safe for human consumption due to the limited amount of moisture for microbial activity. Recalls of these foods due to pathogens such as Salmonella and undeclared allergens have brought attention to the need for improved cleaning and sanitization in dry food manufacturing facilities. In the food industry, cleaning and sanitation activities are the most efficient methods to prevent microbial contamination; however, water is most often required to deliver cleaning and sanitation agents. A well‐written and properly implemented sanitation standard operating procedure can take care of microbial and allergen cross‐contamination. Nevertheless, there are unique challenges to cleaning and sanitation processes for low‐moisture food manufacturing facilities. The introduction of moisture into a low‐moisture food environment increases the likelihood of cross‐contamination by microbial pathogens. Hence, the use of water during cleaning and sanitation of dry food manufacturing facilities should be limited. However, much less research has been done on these dry methods compared to wet sanitation methods. This review discusses recent foodborne outbreaks and recalls associated with low‐moisture foods the accepted methods for cleaning and sanitation in dry food manufacturing facilities and the limitations of these methods. The potential for air impingement as a dry‐cleaning method is also detailed. [ABSTRACT FROM AUTHOR]

The use of air jet impingement to remove residues from surfaces in food manufacturing operations offers an alternative to the use of water and liquid cleaning agents. During this investigation, air impingement was used to remove nonfat dry milk (NFDM) residues from a stainless‐steel surface. The influence of the water activity (aw) of the residue, the time after the residue reached an equilibrium water activity, and the thickness of residue at the time of removal from the surface have been investigated. All three factors had a significant effect on the time for removal. An increase in the water activity, the time at equilibrium, the sample thickness, or a combination of all three resulted in an increase in the time required to remove the deposits. Visible changes in the structure of deposits were observed as NFDM samples equilibrated to water activities above 0.43. NFDM residues with water activities less than 0.33 were removed within 1 s of using air impingement regardless of wall shear stress. When the water activities were greater than 0.50, the thickness of deposit was greater than 1 mm, and the time after reaching an equilibrium water activity was over 7 days, more than 5 min of air impingement with wall shear stress over 9.48 Pa was required to remove the residue. The results from these experiments indicated that air impingement has the potential to provide effective cleaning in manufacturing facilities for low‐moisture foods. Practical Application: The introduction of water in low‐moisture food environments is often undesirable due to the possibility of pathogenic microorganism growth. The normal cleaning operations in the food industry use water as a cleaning agent. This study evaluates the application of air impingement technology as a dry‐cleaning method. [ABSTRACT FROM AUTHOR]

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the literature, there are few reports indicating hydrocolloids as a factor capable of reducing the amount of acrylamide formed in food. Therefore, the aim of the study was to examine the ability of soluble oat fiber to reduce the amount of acrylamide formed in the process of obtaining rusks. The effect of the concentration of β-glucans in oat fiber preparations at 20% and 30% and the amount of preparations used at 10%, 15%, and 20% was investigated. On the basis of the obtained test results, it was shown that the most optimal concentration of oat fiber preparation in rusks recipe is at 15%, regardless of the content of β-glucan in it. This concentration makes it possible to reduce the amount of acrylamide formed in baked goods and rusks by ~70% and ~60%, respectively, while maintaining the desired physical and chemical properties of the product. In addition, it was shown that the browning index and water activity strongly correlate with the content of acrylamide in rusks, which makes them good markers of this compound in rusks. The use of hydrocolloids in the form of oat fiber preparations with different contents of β-glucan as a tool for reducing the amount of acrylamide in rusks, at the same time, offers the possibility of enriching these products with a soluble dietary fiber with health properties. [ABSTRACT FROM AUTHOR]

In this study, the effect of environmental aw on microbial inactivation by intense pulsed light (IPL) was investigated. Three different microorganisms (Gram-positive bacteria, Gram-negative bacteria, and yeast) were used as test organisms. The effect of environmental aw was assessed by irradiating each microbial suspension in sodium chloride solutions with different environmental aw levels (0.99–0.80). As the aw decreased, the aggregation of intracellular material of cell interior was changed and the cell number was increased. However, there was no significant difference in microbial reduction according to the aw after the 0.23–3.05 J/cm2 of IPL treatment. It was confirmed that yeast had the highest resistance to IPL because of the differences in cell structure and cell wall components between yeast and bacteria. Additional research is needed to clearly understand the inactivation mechanism according to the type of microorganism by controlling aw using various solutes. [ABSTRACT FROM AUTHOR]

The effects of water content and water activity on the lipid stability of air-dried hairtail (Trichiurus haumela) were investigated during chilled storage. Air-dried hairtail samples with high and low water contents were comparatively analyzed over 8 days of storage at 4 °C. The results indicated that the decreases in water activity and increases in the NaCl content significantly inhibited lipid oxidation in the air-dried hairtail samples. The peroxidation value (PV), conjugated diene value (CD), thiobarbituric acid reactive substance (TBARS) value, and p-anisidine value (p-AnV) of the air-dried hairtail significantly increased with the extension of storage time. The low water content significantly inhibited the activity of neutral and alkaline lipase, in addition to lipoxygenase, and retarded the rapid increases in the non-esterified fatty acid (NEFA) content in the hairtail samples. The correlation analysis results showed that the TBARS, p-AnV, and lipase activity were positively correlated in the air-dried hairtail samples, and the lower water content significantly inhibited the progress of lipid oxidation. This study offers a theoretical framework for the industrial processing and storage of air-dried hairtail products. [ABSTRACT FROM AUTHOR]

Expanding the assortment of low-fat yogurt with natural structuring sweeteners and regulated quality indicators is an actual direction of scientific research. The purpose of the study is to study the patterns of influence of the products of enzymatic hydrolysis of corn starch with different dextrose equivalents on the rheological, physical and chemical characteristics of yogurt. Тhe functional and technological properties of starch products of different chemical composition were studied-maltodextrin MD-10, glucose syrup IG-42 and glucose-fructose syrup GFS-42. The possibility of completely replacing dry skimmed milk and sugar in the composition of yogurt with a fat content of 1% drinkable with an equivalent content of dry substances of maltodextrin MD-10 and glucose syrup IG-42, which ensure the formation of rheological characteristics inherent high-quality yogurt. Yogurt with sucrose, which inhibits the organization of macromolecular chains of milk proteins, has the lowest thixotropic ability, and yogurt with maltodextrin MD-10 and glucose syrup IG-42 has the highest. The predominance of higher sugars in the composition of MD-10 maltodextrin lengthens, and the increased content of monosaccharides in GFS-42 accelerates the duration of fermentation of milk mixtures in the technological process of production of yogurt with a fat content of 1.0%. Monosaccharides in the composition of GFS-42 significantly affect the activity of water and at the same time reduce the moisture-retaining capacity of the sour-milk yogurt curd. The degree of influence on the rheological characteristics and moisturebinding capacity of yogurt increases with a decrease in the dextrose equivalent of starch products in the following sequence: GFS-42 → IG42 → MD-10. So, it is the dextrose equivalent of starch products that is an objective criterion of their technological activity as part of yogurt. The results of the study will allow purposeful management of the process of forming low-fat yogurt quality indicators. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of specially-shaped packet materials on the moisture retention for cigarettes, the isothermal adsorption curves of cut tobacco, cigarette paper, tipping paper, sulfate paper, filter rod and packet materials were established post production. The correlation curves between water activity and moisture contents were fitted by the DLP model equation, and the fitting results were verified. According to the law of mass conservation and the fitting results of the DLP equation, a prediction method for the moisture content in each material used in the specially-shaped packet was constructed, and a verification test of the method was conducted. The results showed that: 1) The determination coefficients of the fitting results were all higher than 0.999 0 by using the DLP model equation, and the average relative errors of the measured and predicted moisture contents were all less than 5%, indicating that the equation was suitable for evaluating the performance of the materials. 2) Under the condition of 90% relative humidity, the specially-shaped cigarette packet with a good moisture sealing degree could better isolate the influence of the environmental humidity within 15 days. 3) The same cigarettes were packed in the packets balanced at different relative humidity, and the moisture content in the packet system could reach full equilibrium after 18 days. 4) The prediction method optimized with the law of conservation of mass and the fitting results of the DLP model equation was accurate for the moisture content in each of the material in the packet system. The packets with different moisture contents in the materials had different effects on cut tobacco, filter rod, and sulfate paper, which indicated that the moisture content in cigarettes could meet the quality requirements by controlling the moisture contents in the materials within a reasonable time range. [ABSTRACT FROM AUTHOR]

Water-soluble carbohydrates commonly exist in an amorphous state in foods and undergo glass-rubber transition (glass transition) at the glass transition temperature (Tg). The critical water content (Wc) and critical water activity (awc) are the water content and water activity (aw) at which the glass transition occurs at 298 K (typical ambient temperature), respectively. For amorphous water-soluble carbohydrates, Wc can be predicted from the Tg of anhydrous solid (Tgs) using previously reported equations. However, an approach for predicting awc is still lacking. This study aimed to establish an awc-predictive approach for amorphous water-soluble carbohydrates based on Tgs. First, the water sorption isotherms of four hydrogenated starch hydrolysates were investigated, and the results were analyzed using the Guggenheim-Anderson-de Boer (GAB) model. Second, the effect of Tgs on the GAB parameters (C, K, and Wm) was evaluated using the Tgs values reported in previous literatures. C and Wm decreased and increased logarithmically, respectively, with increasing 1/Tgs. K was fixed to 1 (constant), as it showed little variation. These results enabled the prediction of the GAB parameters from Tgs. The GAB model could then predict awc from Wc, which was determined using the previously established equations. The predicted awc values were in good agreement with the experimentally determined awc. Additionally, we demonstrated that this awc-prediction approach is also applicable to amorphous water-soluble electrolytes and partially water-insoluble carbohydrates. Thus, this approach can be used for the quality control of amorphous water-soluble carbohydrates and carbohydrate-based foods. [ABSTRACT FROM AUTHOR]