Food Science and Technology International最新文献

Incorporating carotenoids into sodium alginate films can give them functional properties for food packaging applications. The lycopene and β-carotene were included in the biopolymer matrix at 0.1%, 0.3%, and 0.5% (g carotenoid/g polymer). There was no significant difference (p > 0.05) in film thickness (45 ± 1 μm) of sodium alginate films with carotenoids. Nevertheless, the low quantity of carotenoids was enough to promote significant variations in the tensile properties of films. The films with lycopene or β-carotene showed lower tensile strength and elongation at break than control films. The carotenoid incorporation promoted a reduction (p < 0.05) in water vapor permeability, mainly by adding 0.5%. In the same way, it improved the light transmission and thermal stability of films and did not affect the water solubility of films. The scanning electron microscopy of films showed a homogeneous surface, but the films with lycopene or β-carotene showed a more compact structure than the control film. The sodium alginate films incorporated with 0.3% lycopene or β-carotene showed a remarkable protective effect on sunflower oil against oxidation compared with traditional commercial plastic packaging under accelerated storage conditions (heat and light). Therefore, they can be considered a potential material for food packaging purposes.

A novel approach in promoting the valorisation of fruit waste as potential bio-ingredients in food applications is gaining research attention in recent times. In the present study, hog plum bagasse (HPB) treated with citric acid alone (0.12 dm³, 99.0% purity) and in synergistic treatment with ultrasound (40 KHz, 400 W, 0.348 W/cm³, 60 min, 80 °C). Treated samples were evaluated for proximate and lignocellulose composition, functional, bioactive, structural, morphology and microbial properties, while the untreated samples served as control. HPB showed varied proximate values with treatment effect. Notably, a significant reduction (42.06%) was observed in fibre content. A similar reduction was observed in the hemicellulose and lignin fraction but improved the yield of the cellulose component. Furthermore, treatment increased bulk density (0.120-0.131 g/cm³), water absorption capacity (5.60-6.35 g/g), swelling power (8.85-9.94 g/g) and solubility index (1.01-2.32%) but reduced oil absorption capacity (7.50-4.15 g/g). All colour parameters were reduced with treatment, while the total phenolic compound and antioxidant capacity of treated bagasse improved by 24.70% and 45.37%. Fourier transform infra-red spectroscopy alterations were observed in the absorption spectra with treatment, while scanning electron microscopestructure in treated samples showed cavity formation. Also, the microbial population was reduced to a non-detectable level after treatment. Ultrasound-assisted treatment of HPB holds a valorisation potential for its food application by relevant agro-based industries.

Pectin methylesterase (PME) is the target-enzyme in orange juice processing, and its inactivation preserves the original juice's cloud, a valuable quality attribute for consumers. This study was primarily undertaken to evaluate the combination of supercritical carbon dioxide (SC-CO₂) and mild temperatures on PME inactivation in the juice. Physicochemical and color parameters were also evaluated. Pressures (P) in the range of 74 to 351 bar, temperatures (T) between 33 °C and 67 °C, and holding times (t) varying from 20 to 70 min were tested using a central composite rotational design. Determination of PME activity, pH, titratable acidity, soluble solids, ratio, lightness, °hue and chroma in freshly extracted/raw and treated juice samples, and total color difference (TCD) between raw and treated juice were carried out. The percentage of PME reduction widely ranged from 13.7% to 91.8%. The variable P had a significant effect (p ≤ 0.05) on TCD and acidity variation. T exhibited a significant effect on the PME reduction, TCD, and soluble solids variation; however, t impacted on the soluble solids variation only. The interaction between P and t (P.t) affected the soluble solids and acidity variation, and T.t affected TCD. The combination of SC-CO₂ and mild temperatures is potentially capable of inactivating PME in orange juice.

Conching is a processing stage of industrial chocolate manufacture that is essential to the development of the sensory and rheological properties of the finished product. It promotes the physicochemical changes leading to flavor, aroma, and flowability refinement by continuously heating, aerating, shearing, and homogenizing chocolate mass during an extended time length. Conching duration is a key processing parameter that depends on the type of chocolate, the quality of primary ingredients, the conche's configuration, and the desired sensory outcome in the chocolate. Shorter cycles are often beneficial to manufacturers, due to increased productivity and reduced energy consumption, but they may be insufficient to fully develop chocolate's desired sensory properties. The present study aimed to shed light on the trade-off between product quality and process efficiency by assessing if varying conching durations were associated with statistically significant differences in the sensory profile and consumer acceptance of milk chocolates with freeze-dried blueberry. Samples were produced under an alternative method of conching prior to ball mill refining, with times investigated being 6, 12, 24, 36, 48, and 72 h, and were subsequently submitted to Quantitative Descriptive Analysis and consumer acceptance test. No statistically significant differences in either sensory profiles or consumer acceptance ratings of samples were observed, with the exception of hedonic values for aroma, indicating that a 6-h conching cycle was already enough to develop the sensory properties of the milk chocolate with freeze-dried blueberry. The feasibility of shorter conching times suggests a potential for energy saving and increased productivity in the production of milk chocolates following the conching prior to ball mill refining concept.

In this study, the effects of fructose levels on yeast growth, metabolic pathways and products, and redox status were investigated by simulated dough medium. The results showed that yeast was subjected to oxidative stress and damage under both sugar-free and high-fructose conditions. Yeast has a strong ability to metabolize pentose phosphate, trehalose, and tricarboxylic acid under sugar-free conditions. In the high fructose environment, yeast preferentially produced trehalose and glycerol in the early stage and gradually increased the metabolism of pentose phosphate in the later stage. Compared with the low fructose concentration, yeast had stronger pentose phosphate and tricarboxylic acid cycle (TCA) metabolism to ensure nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP) content in higher fructose levels. Therefore, sugar-free and high fructose levels affected the growth of yeast cells and yeast responded to fructose levels by regulating the metabolic carbon flow of glycolysis, pentose phosphate, trehalose, and TCA.

The purpose of this study was to create a tool for predicting the growth of total mesophilic bacteria in spinach using machine learning-based regression models such as support vector regression, decision tree regression, and Gaussian process regression. The performance of these models was compared to traditionally used models (modified Gompertz, Baranyi, and Huang models) using statistical indices like the coefficient of determination (R²) and root mean square error (RMSE). The results showed that the machine learning-based regression models provided more accurate predictions with an R² of at least 0.960 and an RMSE of at most 0.154, indicating that they can be used as an alternative to traditional approaches for predictive total mesophilic. Therefore, the developed software in this work has a significant potential to be used as an alternative simulation method to traditionally used approach in the predictive food microbiology field.

In this study, the effects of calcium levels on structure and function of mitochondria under high glucose environment were studied. In the high glucose environment, yeast growth capacity was inhibited, and intracellular reactive oxygen species (ROS) content was increased from 6 h to 12 h, while ROS content was reduced in group with 1 × 10^-1 and 1 g/L CaCl₂ level from 24 h to 36 h. Exogenous calcium addition had a significant effect on the elevation of intracellular Ca²⁺ and cytochrome C content in yeast from 6 h to 12 h; mitochondrial membrane potential decreased with the increase of CaCl₂ level under high glucose levels. Mitochondrial swelling of yeast was influenced by high glucose levels and showed a regulatory dynamic change by Ca²⁺ levels. Isocitrate dehydrogenase activity increased in 1 × 10^-3 g/L CaCl₂ level from 6 h to 12 h, α-ketoglutarate dehydrogenase activity increased with an increase in CaCl₂ level from 6 h to 24 h. Calcium affected the structure and function of mitochondria by regulating the intracellular signal, enzymes in tricarboxylic acid cycle, and cytochrome system of yeast under high glucose stress.

To improve the edible qualities of meatballs, various percentages of pork fat in meatballs were replaced by brown flaxseed flour (BFF) to decrease the fat contents and further optimize the fatty acid compositions. Five different meatball formulations that used 0%, 5%, 10%, 15%, and 20% of flaxseed flour additions were used in which the corresponding amounts pork fat were replaced. The proximate compositions, water activity, pH levels, colors, textures, cooking losses, fatty acid compositions, sensory properties, flavors, and oxidation stabilities of these meatballs were analyzed. Increasing the BFF addition amounts improved the protein and dietary fiber contents, pH levels, fatty acid profiles and oxidation stabilities, but decreased the fat contents, moisture levels, cooking losses, n6/n3 ratios, hardness, and lightness. The volatile flavors of meatballs with different BFF replacement levels were significantly different. According to the sensory evaluation, the use of 5% BFF increased the odor of meatballs without significantly affecting the other sensory scores. This work demonstrated that BFF may be a healthier alternative as pork fat replacer for preparing meatballs.

This research investigates the production of kefir using Turkish and Kazakh kefir grains and commercial starter cultures, followed by storage at 4 °C for 30 days. The study monitors the rheological properties and microbiological characteristics of kefir on the 1^st, 15^th, and 30^th days of storage, as well as during dynamic in vitro gastrointestinal digestion. Kefir samples were passed through a dynamic in vitro gastrointestinal model simulating the digestive processes of the mouth, stomach, and small intestine which was designed in laboratory conditions. Kefir from Turkish kefir grain exhibited the lowest average titratable acidity, apparent viscosity, and flow behavior index, while kefir from Kazakh kefir grain had the highest average pH. Over the storage period, pH and flow behavior index decreased, while titratable acidity, viscosity, and consistency coefficient increased. The kefir samples showed non-Newtonian pseudoplastic flow characteristics. The acetic acid bacteria and Leuconostoc counts of kefir samples produced with commercial starter cultures were higher than those produced with kefir grains, while yeast counts were higher in kefir samples produced with kefir grains. During storage and in vitro gastrointestinal digestion, the number of microorganisms in kefir samples decreased. Turkish kefir grain resulted in the lowest reduction (%) of microorganism counts during in vitro gastrointestinal digestion. These findings shed light on the rheological, microbiological, and in vitro digestive properties of kefir during storage, which may contribute to improving the quality and health benefits of kefir products. The present study revealed that the kefir produced with kefir grains had a lower decrease in the viability of microorganisms compared to the kefir produced with starter culture after passage through the gastrointestinal model, so kefir produced with kefir grains may be more preferred due to its possible health benefits.

High hydrostatic pressure (HHP) is an emerging technology that can be applied to improve the functional properties of emulsified meat products. The aim of this study was to evaluate the effect of HHP (100 and 200 MPa) on low-sodium mortadella produced with high content of mechanically deboned poultry meat (MDPM). Seven treatments were produced: FC (2.5% NaCl - control 1), F1-C (1.25% NaCl - control 2), F1-100 (1.25% NaCl and 100 MPa), F1-200 (1.25% NaCl and 200 MPa), F2-C (1.25% NaCl, 1.60% KCl), F2-100 (1.25% NaCl, 1.60% KCl, 100 MPa), and F2-200 (1.25% NaCl, 1.60% KCl, 200 MPa). Proximate composition, sodium content, emulsion stability, extraction yield of myofibrillar proteins, instrumental color, texture profile, and microstructure of the samples were evaluated. Pressurization and salt reduction did not affect chemical composition (moisture, fat and protein) of the samples, while HHP increased protein extraction, forming a more compact, homogeneous and better distributed gel, improving emulsion stability and increasing mortadella hardness. Therefore, this technique could effectively compensate the deterioration in the protein gel matrix caused by salt reduction. Studies are necessary to investigate the effects of HPP on sensory properties and lipid oxidation of mortadella.