The enhancement effect of mungbean on the physical, functional, and sensory characteristics of soy yoghurt.

Vegetable drinks offer a convenient way to increase the daily intake of vegetables containing vitamins, antioxidants, and fiber. In this study, we discovered that mungbean milk serves as a carbohydrate source during fermentation using lactic acid bacteria (LAB) and enhances the nutritional value of vegetable yoghurt. Mungbean milk reduces pH while titratable acidity increases faster than soybean milk during fermentation. M0S, Soybean milk 100% with added sucrose exhibited the highest titratable acidity after 16 h of fermentation. The acetic acid content of all samples did not show significant changes during fermentation, but the lactic acid content increased. Proximate analysis showed no significant change during fermentation, regardless of the fermentation time and mixing ratio of mungbean to soybean milk. The sucrose content of samples except M0S decreased after 16 h of fermentation. Mungbean milk exhibited high antioxidant activity both before and after fermentation, while M0S showed the lowest antioxidant activity. The results of this study demonstrated the potential application of mungbean milk to improve fermented vegetable drinks using LAB functionally. Fermented mungbean milk yoghurt can be a valuable addition to a healthy and balanced diet for those who consume plant-based diets.

Unveiling targeted spatial metabolome of rice seed at the dough stage using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry imaging.

Rice (Oryza sativa) seeds contain a variety of metabolites, which not only provide energy for their own growth and development, but also are an important source of nutrition for humans. It is crucial to study the distribution of metabolites in rice seeds, but the spatial metabolome of rice seeds is rarely investigated. In this study, Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) imaging was used to reveal the spatial distribution of free soluble sugars (glucose, fructose, sucrose, and maltose), amino acids (9 essential amino acids and 2 amino acids affecting rice eating quality: L-aspartic acid and L-glutamic acid), and 4 metabolites in the flavonoids synthesis pathway (cinnamic acid, naringenin chalcone, naringenin, and dihydrokaempferol) in rice seed at the dough stage. It was found that the 4 free soluble sugars present similar spatial distribution, mainly distributed in the seed cortex and embryo with high abundance. The majority of amino acids are also concentrated in the rice cortex and embryo, while the others are abundant in the whole seed. Besides cinnamic acid distributed in the seed cortex and embryo, the naringenin chalcone, naringenin, and dihydrokaempferol were also found in the endosperm and had lower content. Furthermore, a colocalization phylogenetic tree according to the spatial distribution imaging of each metabolite was constructed. This study revealed the distribution diversity of metabolites in different segmentations of rice seed at the dough stage, providing clues for the nutritional differences between brown rice and white rice, and serving as a reference for people to target a healthy diet.

Interventional effect of compound sugar and salt on the thermal instability behavior of liquid egg yolk.

In this study, the influence of compound sugar (glucose, sucrose, trehalose, and arabinose) and compound sugar and salt (glucose, sucrose, trehalose, arabinose, and NaCl) on the thermal stability of heat-treated liquid egg yolk was explored. The results showed that the addition of 4% compound sugar or 4% compound sugar salt could significantly enhance the heat resistance of liquid egg yolk and increase the denaturation temperature of liquid egg yolk to above 77°C. Moreover, the addition of sugar and salt could improve the functional properties of liquid egg yolk to varying degrees, allowing it to maintain excellent emulsification and soluble protein content after heat treatment. Further analysis using Fourier transform infrared spectroscopy showed that the increase in α-helix content in liquid egg yolk treated with sugar salt also contributes to improving the thermal stability of egg yolk. The method of inhibiting egg yolk aggregation caused by heat treatment provided in this study provides a selective method and theoretical basis for the commercial production of heat-resistant liquid egg yolk.

Consumer acceptability of no added sugar pound cakes under blind and informed testing conditions.

Stevia is an emerging natural high-intensity sweetener. There are negative perceptions of zero-calorie sweeteners, but studies that provide knowledge of these sweeteners improve their perception. This study evaluated consumer acceptability of a zero-sugar bakery product under blind and informed conditions (n = 96) along with physicochemical analysis of the products. Rebaudioside A (Reb A) and the new types of stevia (Rebs D and M) with sugar as a control were used to formulate pound cakes. Panelists evaluated the overall hedonic impressions (aroma, texture, flavor, and aftertaste) and intensity (sweetness and bitterness) of the cakes under blind and informed conditions with an enforced 2-week break between evaluations. During the informed session, a document was provided prior to evaluating samples that included stevia's health benefits and the nutritional facts panels for the cakes. The cakes underwent volatile profile (electronic nose [e-nose]) and water activity (aw ) analysis. Overall, stevia cakes showed an increase in flavor and texture liking during the informed session when compared to the blind session, but only Reb A showed a significant difference (p < 0.05). The increase in liking scores indicated that information positively affected the consumer's perception of the stevia-sweetened cakes attributes. The e-nose confirmed differences in aroma. There was a significant difference in aw of the samples Rebs A, D, M versus sucrose (p < 0.05). No significant differences were observed among the Rebs (p > 0.05). This study illustrates that stevia, despite non-browning or fermenting, can be used in a practical baking application, and product-related information impacts consumer acceptability. PRACTICAL APPLICATION: This study demonstrates that product-related information may have an impact on the consumer acceptability of the product. Through potential labeling improvements, overall consumer perception and acceptability of zero-sugar added or low-sugar products could be improved. This study also illustrates that stevia, despite being a non-browning or fermenting sugar alternative, can be used in a practical baking application.

Use of coconut sugar as an alternative agent in osmotic dehydration of strawberries.

This study aimed to evaluate coconut sugar (CS) as an alternative osmotic agent to sucrose for the osmotic dehydration (OD) of strawberries. OD was performed by immersing strawberries cut into 13.6 ± 0.4 mm edge cubes in osmotic solutions of CS or sucrose, at two different concentrations (40% and 60%, w/w), with and without application of vacuum (AV) in the first 20 min of the process. The total OD time was 300 min. Evaluations of the kinetics of solid gain (SG), water loss (WL), and weight reduction (WR) were performed at 30, 60, 120, 180, 240, and 300 min. SG, WL, and WR increased over the OD time and showed values of up to 7.94%, 63.40%, and 55.94%, respectively. AV increased WL, WR, shrinkage, pH, and total color difference and decreased anthocyanin, ascorbic acid (AA), phenolic, and antioxidant contents. The higher concentration led to higher SG, WL, WR, shrinkage, hardness, and lower moisture content, water activity, anthocyanin, AA, phenolic, and antioxidant contents. The use of CS instead of sucrose had little influence on strawberry properties, except pH and color responses. The optimal treatment was using a 60% CS solution without AV, showing a very distinct color change, hardness increased by approximately 4.5 times and maintenance of acidity, anthocyanins, AA, total phenolics, and antioxidants of 38.0%, 39.6%, 11.8%, 30.0%, 31.1%, and 30.3%, respectively, compared to fresh strawberries. PRACTICAL APPLICATION: Osmotic dehydration of fruit is a process traditionally carried out using sucrose. However, increasing health concerns have made consumers seek alternative sugars to sucrose. The use of coconut sugar made it possible to produce osmo-dehydrated strawberries different from the traditional one, maintaining product quality and process efficiency.

Modelling of perceived sweetness in biscuits based on sensory analysis as a new tool to evaluate reformulation performance in sugar reduction studies.

Sugar reduction in foods is of global interest in food science and industry to limit excessive calorie intake for healthier nutrition. Therefore, a modified Weibull model-based approach is presented here to relate sweetness perception with sugar concentration for the first time. The model was tested by using sweetness perception data obtained from sensory analysis of biscuits (wholewheat flour, whey or hydrolysed pea protein, different sucrose forms, ethylvanillin, furaneol, phenylacetaldehyde) using a line scale and untrained panellists. Sweetness scores increased 56%, 59%, 41% by the addition of wholewheat flour, proteins, or aroma compounds at 17% sucrose containing biscuits, respectively. Wholewheat flour and proteins boosted Maillard reaction products imparting baked/caramel-like flavour. The Weibull model well fitted to the sweetness perception data with a sigmoidal curve and high predicting power. This approach allows to explain how much sugar reduction can be achieved to reach a targeted sweetness perception without performing further sensory analysis.

Ambient mass spectrometry and near-infrared spectroscopy - a direct comparison of methods for the quantification of sucralose in e-liquids.

E-liquids have become increasingly popular in society in recent years. A wide variety of flavors and nicotine strengths make it possible for every user to get a product according to their wishes. Many of these e-liquids are marketed with countless different flavors, which are often characterized by a strong and sweet smell. Sweeteners, such as sucralose, are therefore commonly added as sugar substitutes. However, recent studies have shown the potential formation of highly toxic chlorinated compounds. This can be explained by the high temperatures (above 120 °C) within the heating coils and the used basic composition of these liquids. Nevertheless, the legal situation is composed of proposals without clear restrictions, only recommendations for tobacco products. For this reason, a high level of interest lies within the establishment of fast, reliable and cost-effective methods for the detection of sucralose in e-liquids. In this study, a number of 100 commercially available e-liquids was screened for sucralose in order to identify the suitability of ambient mass spectrometry and near-infrared spectroscopy for this application. A highly sensitive high-performance liquid chromatography coupled to a tandem mass spectrometer method was used as reference method. Furthermore, the advantages and limitations of the two mentioned methods are highlighted in order to provide a reliable quantification of sucralose. The results clearly revile the necessity for product quality due to the absence of declaration on many of the used products. Further on, it could be shown, that both methods are suitable for the quantification of sucralose in e-liquids, with beneficial economic and ecological aspects, over classical analytical tools including high-performance liquid chromatography. Clear correlations between the reference and novel developed methods are displayed. In summary, these methods enable an important contribution to ensure consumer protection and elimination of confuse package labelling.

Effects of gamma irradiation on the sensory and metabolic profiles of two peach cultivars.

BACKGROUND: The suitability of commercial peaches for minimal processing (MP) is limited, mainly due to shortened shelf-life. Gamma irradiation has emerged in MP fruits as a promising technology. This study aimed to investigate the effects of gamma irradiation on the sensory and metabolic profiles of MP peaches from two cultivars - 'Forastero' (FT) and 'Ruby Prince' (RP) - and evaluate the relationship between both profiles. MP peaches were packaged and divided into two groups: one without additional treatment (K) and the other subjected to gamma irradiation (1.0 kGy, I- irradiation treatment), making a total of four samples (FTK, FTI, RPK and RPI). The sensory profile was carried out by an assessor panel. Metabolite analysis was accomplished by gas chromatography-mass spectrometry. RESULTS: Irradiation significantly affected color, homogeneity, peach aroma, total flavor intensity, peach flavor, sweetness and juiciness in FT, increasing their intensities. In the RP cultivar, irradiation increased brightness, total aroma intensity, peach aroma, and flavor and texture descriptors. Regarding metabolites, only malic acid and sucrose increased their concentrations in the irradiated samples. Partial least squares showed that sucrose was mainly correlated with sweet, total aroma intensity and peach flavors, and linked with FTI sample. Bitter along with peach aroma and total intensity flavor were associated with RPI sample. CONCLUSION: The applied dose accelerated the ripening process of the peach. The study highlights the importance of complementing sensory analysis with metabolomics tools to optimize fruit quality in minimally processed peaches. © 2023 Society of Chemical Industry.

Temporal sweet taste dominance according to adult body mass index classification.

Excess adipose tissue is associated with basic tastes perception change, which can negatively affect food choices. However, the effect of overweight and obesity on sensory perception is not clearly explained in the literature yielding heterogeneous results. The present investigation aimed to investigate the temporal dominance of sweet taste according to body mass index (BMI) classification in adults during the ingestion of five passion fruit nectar samples prepared with different sucrose concentrations. The temporal dominance of sensations methodology was applied, which allowed the representation of the stimuli assessed in dominance curves, considering a significant difference in Fisher's exact test (p ≤ 0.05). The attributes evaluated were sweet taste, bitter taste, acidic taste, astringency, passion fruit flavor, metallic taste, or none of the previous options. The sensory analysis was performed with the participation of ninety adult consumers, divided into three groups: EG = eutrophic, WG = overweight, and OG = obesity group, according to the BMI classification. Between the groups a difference in the perception of the attribute "sweet taste" was observed: The EG demonstrated perception of the stimulus in food samples at lower sucrose concentrations, whereas WG and OG showed a higher rate of sweet taste dominance in the food samples with higher concentration of sucrose. Overweight and obese individuals have a lower sensory perception of sweet taste and require a greater amount of sucrose to producing sensory dominance of the attribute "sweet taste" when compared to eutrophic individuals. PRACTICAL APPLICATION: Overweight and obese individuals may experience taste perception in foods in a different way. This study investigated the dominance of sweet taste perception in a fruit beverage by adults with adequate weight and overweight. The results of the tests support the hypothesis that obese and nonobese individuals differ in the sweet taste perception, which can help to understand which factors are involved in sensory perception and food consumption, in addition to providing subsidies for the nonalcoholic beverage industry to elaborate products with new alternatives for concentration and/or replacement of sucrose.

Characterization of the Polar Profile of Bacon and Fuerte Avocado Fruits by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry: Distribution of Non-structural Carbohydrates, Quinic Acid, and Chlorogenic Acid between Seed, Mesocarp, and Exocarp at Different Ripening Stages.

Avocado fruit growth and development, unlike that of other fruits, is characterized by the accumulation of oil and C7 sugars (in most fruits, the carbohydrates that prevail are C6). There are five essential carbohydrates which constitute 98% of the total content of soluble sugars in this fruit; these are fructose, glucose, sucrose, d-mannoheptulose, and perseitol, which together with quinic acid and chlorogenic acid have been the analytes under study in this work. After applying an efficient extraction procedure, a novel methodology based on hydrophilic interaction liquid chromatography coupled to mass spectrometry was applied to determine the levels of these seven substances in tissues─exocarp, seed, and mesocarp─from avocado fruits of two different varieties scarcely studied, Bacon and Fuerte, at three different ripening stages. Quantitative characterization of the selected tissues was performed, and the inter-tissue distribution of metabolites was described. For both varieties, d-mannoheptulose was the major component in the mesocarp and exocarp, whereas perseitol was predominant in the seed, followed by sucrose and d-mannoheptulose. Sucrose was found to be more abundant in seed tissues, with much lower concentrations in avocado mesocarp and exocarp. Quinic acid showed a predominance in the exocarp, and chlorogenic acid was exclusively determined in exocarp samples.

l-Glutamate maintains the quality of apple fruit by mediating carotenoid, sorbitol and sucrose metabolisms.

BACKGROUND: l-Glutamate is involved in many important chemical reactions in horticultural products and improves postharvest disease resistance. Quality decline of apple fruit caused by senescence and fungus invasion often leads to tremendous losses during logistics. This study was performed to evaluate the variations of quality attributes, carotenoid, sorbitol and sucrose metabolisms in apples (cv. Qiujin) after l-glutamate dipping treatment. RESUITS: l-Glutamate immersion maintained high values of L*, a* and b*, flesh firmness, titratable acidity, as well as the total soluble solids, soluble sugar, reducing sugar and ascorbic acid contents in apples. l-Glutamate also decreased mass loss, respiratory rate and ethylene release, enhanced sucrose synthase-cleavage, acid invertase and neutral invertase activities, whereas reduced sorbitol dehydrogenase, sucrose phosphate synthase, sucrose synthase synthesis and sorbitol oxidase activities in apples. Moreover, l-glutamate inhibited lutein, ß-carotene and lycopene accumulation, and down-regulated phytoene synthase, lycopene ß-cyclase, ζ-carotene desaturase, phytoene desaturase, carotenoid isomerase, ζ-carotene isomerase and carotenoids cleavage dioxygenase gene expressions, but up-regulated 9-cis-epoxycarotenoid dioxygenase gene expression in apples. CONCLUSION: Postharvest l-glutamate dipping treatment can keep apple quality by modulating key enzyme activity and gene expression in sorbitol, sucrose and carotenoid metabolisms. © 2023 Society of Chemical Industry.

Effect of sweeteners and carbonation on aroma partitioning and release in beverage systems.

The effect of monosaccharides (glucose, fructose and galactose) and disaccharides (sucrose and lactose) at 10, 20 and 30 % w/v on the in-vitro aroma partitioning of C4 - C10 aldehydes and ethyl esters, as well as limonene (concentration of aroma compounds at 1 µg mL-1), was studied using atmospheric pressure chemical ionisation-mass spectrometry. An increase in sugar concentration from 0 to 30 % w/v resulted in a significant increase in partitioning under static headspace conditions for the majority of the compounds (p < 0.05), an effect generally not observed when 10 % w/v sucrose was substituted with low-calorie sweeteners (p > 0.05). The complexity of the system was increased to model a soft drink design - comprising water, sucrose (10, 20 and 30 % w/v), acid (0.15 % w/v), carbonation (∼7.2 g/L CO2) and aroma compounds representative of an apple style flavouring, namely ethyl butanoate and hexanal (10 µg mL-1 each). Although the addition of sucrose had no significant in-vivo effect, carbonation significantly decreased breath-by-breath (in-vivo) aroma delivery (p < 0.05). To understand the physical mechanisms behind aroma release from the beverage matrix, the effect of sucrose on the kinetics of the matrix components was explored. An increase in sucrose concentration from 0 to 30 % w/v resulted in a significant decrease in water activity (p < 0.05), which accounted for the significantly slower rate of self-diffusion of aroma compounds (p < 0.05), measured using diffusion-ordered spectroscopy-nuclear magnetic resonance spectroscopy. No significant effect of sucrose on carbon dioxide volume flux was found (p > 0.05).

Ongoings in the apple watercore: First evidence from proteomic and metabolomic analysis.

The presence of watercored fruit with translucent mesocarp has attracted immense attention due to its unique morphology and taste, however, the metabolic reconstruction between watercored and non-watercored tissues remain elusive. Herein, the combined proteomic and metabolomic approach was carried out to characterize the protein abundance and metabolic profile in watercored apple. Results demonstrated that carbohydrate metabolism was prioritized enriched in watercored apple, including highly accumulated sucrose and sugar alcohols, and the increased level of transcription factor WHIRLY2 (WHY2), which is required in sugar reallocation. More than 50% overlap of differently abundant proteins involved in calcium ion binding, starch and sucrose metabolism implied the involvement of calcium signaling in watercore development. Moreover, significantly lower calcium content was detected in watercored apples. Sucrose synthase (SUSY) protein, which is involved both in calcium ion binding and sugar metabolism, was the potential basis of apple watercore development, which provided a likely candidate in regulation of apparent quality.

Characterization and shelf stability of sweetened condensed milk formulated with different sucrose substitutes during storage.

Sweetened condensed milk (SCM) is a value-added milk product with extended shelf life and high levels of nutrition. The high level of sucrose may lead to health problems. Many studies have focused on the reduction of sucrose but seldomly on different combination of sugar substitutes. This study aims to find an ideal sucrose substitution through physiochemical, microbiological and sensory properties of SCM under different storage times. The results demonstrated that substitution with 20% trehalose, 5% lactulose and 15% erythritol resulted in similar sensory and color as control group. The volatile flavor analysis showed that substitution with 30% trehalose, 5% lactulose and 5% polyols was the most similar and hexanoic acid was the symbolistic flavor. Sucrose replacement increased the antibacterial effect and Staphylococcus, Penicillium, Apiotrichum and Candida were widely present. Substitution with 30% trehalose, 5% lactulose and 5% polyols resulted in the most similar water activity, texture, aroma and microbial diversity.

Sugar Concentration, Nitrogen Availability, and Phylogenetic Factors Determine the Ability of Acinetobacter spp. and Rosenbergiella spp. to Grow in Floral Nectar.

The floral nectar of angiosperms harbors a variety of microorganisms that depend predominantly on animal visitors for their dispersal. Although some members of the genus Acinetobacter and all currently known species of Rosenbergiella are thought to be adapted to thrive in nectar, there is limited information about the response of these bacteria to variation in the chemical characteristics of floral nectar. We investigated the growth performance of a diverse collection of Acinetobacter (n = 43) and Rosenbergiella (n = 45) isolates obtained from floral nectar and the digestive tract of flower-visiting bees in a set of 12 artificial nectars differing in sugar content (15% w/v or 50% w/v), nitrogen content (3.48/1.67 ppm or 348/167 ppm of total nitrogen/amino nitrogen), and sugar composition (only sucrose, 1/3 sucrose + 1/3 glucose + 1/3 fructose, or 1/2 glucose + 1/2 fructose). Growth was only observed in four of the 12 artificial nectars. Those containing elevated sugar concentration (50% w/v) and low nitrogen content (3.48/1.67 ppm) were limiting for bacterial growth. Furthermore, phylogenetic analyses revealed that the ability of the bacteria to grow in different types of nectar is highly conserved between closely related isolates and genotypes, but this conservatism rapidly vanishes deeper in phylogeny. Overall, these results demonstrate that the ability of Acinetobacter spp. and Rosenbergiella spp. to grow in floral nectar largely depends on nectar chemistry and bacterial phylogeny.

Sugar profiles modulation of mangoes during osmotic dehydration in agave syrup solutions.

Chemical interaction and multicompound competition were investigated on solids gain and carbohydrate profiles evolution during osmotic dehydration of mangoes. Tommy Atkins mango slices (0.4 cm and 1.5 cm thickness) were osmotically processed at 40°C for up to 4 h and 8 h, respectively. Osmotic solutions (60 °Brix) were separated in two categories: single solute (sucrose, glucose, fructose) and multisolute (agave syrup, alone or with additions of 5% inulin or 0.1-0.3% xanthan gum) solutions. High performance liquid chromatography (HPLC) analysis was carried out on treated mango to determine sugar profiles evolution during osmotic dehydration and final product concentrations. Findings pointed out that composition of osmotic solution may modulate mango sugar profiles by triggering uptake or loss of sugar according to different phenomena: chemical potential gradient, lixiviation, prevailing mass transfer, formation of carbohydrate barrier, and solution viscosity. Mango was enriched with the solute present in the single solute osmotic solution, while it lost its own native sugars, which were absent in the osmotic solution. Increasing sample thickness reduces individual sugar uptake or loss in mango treated with both single and multisolute solutions. Significant differences in mono solute solution behavior were found for sucrose due to its capability to form a sugar layer outside the surface of thicker samples, which was shown by scanning electron microscopy (SEM) images, a barrier markedly hindering the sucrose uptake or loss. Addition of polysaccharides (particularly xanthan gum) was found to have an impact of lowering mango individual sugar uptake (18-30%). Practical Application These results will help in understanding the mechanisms by which gain of individual sugars could be reduced and composition could be modulated during osmotic dehydration of fruits. Thus, the findings in this work could lead to production of low-sugar content, osmotically processed mango snacks, enriched with inulin, enhancing their dietary and marketable value.

Phenylpropanoids from Sparganium stoloniferum and their antiplatelet aggregation activities.

Four new ferulic acid sucrose esters, ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-2',6'-O-diacetylglucopyranoside (1), ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-2',4'-O-diacetylglucopyranoside (2), ß-D-(6-O-trans-feruloyl)fructofuranosyl-a-D-2',4',6'-O-triacetylglucopyranoside (3), ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-4',6'-O-diacetylglucopyranoside (4), together with four known phenylpropanoids (5-8) were isolated from the rhizome of Sparganium stoloniferum (Graebn.) Buch.-Ham. ex Juz. Their structures were elucidated by chemical evidence and spectral analysis. Compounds 1-8 exhibited obvious inhibitory effects on ADP-induced platelet aggregation.

Selective detection of starch in banana fruit with Raman spectroscopy.

To develop an analytical method for rapid quantification of starch in agricultural produce, we measured the Raman spectra of ripening banana fruit and compared the obtained data to those of standard starch, sugar, and fiber chemical samples. Standard starches exhibited distinctive Raman bands, which were similar to the spectral features in green banana before ripening. Moreover, these banana-derived Raman bands gradually weakened during 10 d of storage. Standard sugars (glucose, sucrose, and fructose) exhibited Raman bands in both solid and liquid states, whereas standard fibers exhibited broad spectra and no such bands. Although the sugar content increased, no sugar bands were observed in the banana fruit even after ripening. A correlation was found between the Raman bands and starch content obtained by chemical analysis. These results demonstrate that Raman spectroscopy can selectively provide information regarding starch in banana fruit and be applied as an analytical method for rapid starch quantification.

Instant quantification of sugars in milk tablets using near-infrared spectroscopy and chemometric tools.

Milk tablets are a popular dairy product in many Asian countries. This research aimed to develop an instant and rapid method for determining sucrose and lactose contents in milk tablets using near-infrared (NIR) spectroscopy. For the quantitative analysis, a training set composed of laboratory-scale milk samples was generated based on a central composite design (CCD) and used to establish partial least squares (PLS) regression for the predictions of sucrose and lactose contents resulting in R2 values of 0.9749 and 0.9987 with the corresponding root mean square error of calibration (RMSEC) values of 1.69 and 0.35. However, the physical difference between the laboratory-scale powder and the final product milk tablet samples resulted in spectral deviations that dramatically affected the predictive performance of the PLS models. Therefore, calibration transfer methods called direct standardization (DS) and piecewise direct standardization (PDS) were used to adjust the NIR spectra from the real milk tablet samples before the quantitative prediction. Using high-performance liquid chromatography (HPLC) as a reference method, the developed NIR-chemometric model could be used to instantly predict the sugar contents in real milk tablets by producing root mean square error of prediction (RMSEP) values for sucrose and lactose of 5.04 and 4.22 with Q2 values of 0.7973 and 0.9411, respectively, after the PDS transformation.

Impact of Different Storage Regimes on the Levels of Physicochemical Characteristics, Especially Free Acidity in Talh (Acacia gerrardii Benth.) Honey.

This study investigates how storage conditions (temperature and duration) may affect the physicochemical parameters, especially free acidity (FA), of Talh honey originating from Acacia gerrardii that have naturally high FA levels. Fresh Talh honey samples were kept at 0, 25, 35, and 45 °C, and analyzed monthly over a period of eight months. The Talh honey was monofloral with 69% A. gerrardii pollen content. The free acidity (FA) of freshly harvested Talh honey samples was higher (93 ± 0.3 meq/kg) than that of standard limits (≤50 meq/kg) and remained stable at 0 °C throughout the storage period. A significantly increase in FA started to occur after storage for 6 months at 25 °C (103 ± 0.2 meq/kg), 2 months at 35 °C (108 ± 0.3 meq/kg), and 1 month at 45 °C (112 ± 0.3 meq/kg). After 8 months of storage, the highest FA level was recorded at 45 °C (159 ± 0.5 meq/kg), followed by 127 ± 0.3 meq/kg at 35 °C, 105 ± 0.2 meq/kg at 25 °C, and 94 ± 0.3 meq/kg at 0 °C. It was found that 0 °C was an appropriate temperature for storing honey for long time. The electrical conductivity (EC) of fresh Talh samples (1.46 ± 0.0 mS/cm) was above the accepted limit (≤0.8 mS/cm), which was slightly increased (non-significant) throughout the storage period under all the storage temperatures. Hydroxymethylfurfural (HMF), diastase activity (DN), and reducing sugars (RSs) showed normal levels only at 0 °C and 25 °C throughout the storage period. However, HMF exceeded the standard limits after the first month at 45 °C (127 ± 9.6 mg/kg) and after the second month at 35 °C (90 ± 23.5 mg/kg), DA decreased below standard limits after the second month (5 ± 1 DN) under 45 °C and after the seventh month under 35 °C (7 ± 2 DN, and RSs decreased below 60% after 2 months under 45 °C and after 6 months at 35 °C. The physicochemical parameters (moisture content, pH, color, and sucrose) were the least affected and were within the standard range throughout the storage period under all the storage temperatures. The levels of FA and EC in fresh Talh samples were higher than the acceptable limits. The moisture content, pH, color, and sucrose content were not affected by storage conditions and remained within the acceptable limits. HMF, DA, and RSs were significantly affected by storage conditions only at 35 and 45 °C. The storage of honey at low temperatures (0 and 25 °C) for up to eight months presented the least amount of changes in the honey, and the honey was unchanged from its fresh status. Honey storage at 35 and 45 °C resulted in significant changes. It is recommended that Talh honey, which normally has high acidity levels, should be stored at temperatures not exceeding 25 °C.