Journal of Food Science最新文献

Diabetes is a major health concern and is approaching epidemic proportions worldwide. In 2021, diabetes mellitus was responsible for 6.7 million deaths across the globe. Mortality due to diabetes is predicted to rise nearly 10-fold by 2030 and 783 million by 2045. Wheat starch, which constitutes about 70% of the endosperm, is a key component of wheat grain. The rapid hydrolysis of wheat starch can result in elevated postprandial glucose levels, leading to diabetes. The increase in blood glucose levels is primarily due to carbohydrate hydrolysis, catalyzed by the enzymes α-amylase and α-glucosidase. Although various medications are available for treating diabetes, most of them are costly and may lead to adverse effects. Natural herbs like fenugreek are recommended in traditional medicine for regulating blood glucose levels. This investigation aimed to study the effect of fenugreek seed extract (FSE) on in vitro starch hydrolysis by pancreatic α-amylase and the ultrastructure of starch. Wheat cultivars were characterized for their total starch, amylose content, and resistant starch content, and were screened for their predicted glycemic index. Microscopic studies were conducted to analyze the size and shape of starch granules and to compare native starch with starch treated with FSE. Significant inhibition of enzymatic starch hydrolysis was observed with FSE, with the maximum inhibitory effect caused by 0.2% FSE. These findings suggest that fenugreek could play a role in controlling blood glucose levels by reducing wheat starch hydrolysis and could be effective in managing diabetes.

Listeria monocytogenes is ubiquitous in nature and persistent in food-processing facilities, farms, retail stores, and home and restaurant kitchens. Current research suggests ready-to-eat (RTE) products (including RTE hummus and fresh produce) to be of increasing interest and concern. These foods are typically stored at refrigeration temperatures suited to the survival of L. monocytogenes and are consumed without further processing. Since L. monocytogenes is ubiquitous in agricultural environments, the cultivation of fresh produce predisposes it to contamination. The contamination of RTE foods originates either from raw ingredients or, more commonly, from cross-contamination within food-processing facilities. Research on the food-processing environment has been recommended to reduce the incidence of L. monocytogenes in foods. The consumption of contaminated foods by immunocompromised individuals causes invasive listeriosis, with a 20% to 30% fatality rate despite treatment. The emergence of antibiotic-resistant strains has reduced the effectiveness of modern medicine and may increase morbidity and mortality. Without epidemiological surveillance and identifying trends in disease determinants, no action can be taken to improve food safety and mitigate the risk of such outbreaks.

Fermentation is critical for producing high-quality cocoa, yet its kinetics and resulting chemical and sensory outcomes are poorly understood and thus difficult to manage. Cocoa sweatings (CS), the liquid runoff produced early during fermentation and typically drained off, may beneficially affect fermentation outcome when added back into the fermenting mass. Here, we report how back-addition of CS affects composition and sensory perception of roasted cocoa liquor after 5, 6, and 7 days of fermentation. Cocoa liquor (= 100% chocolate) made from beans fermented for 5 days with the addition of CS were similar in sensory perception to those fermented for 7 days without added CS. Twenty-one flavor compounds showed similar patterns to the sensory results: In the beans fermented with CS, these compounds remained at similar levels after 5, 6, and 7 days of fermentation, while the same compounds significantly changed in the samples fermented conventionally, without CS addition. These results suggest a link between changes in flavor composition and sensory differences in roasted cocoa. Future work is needed to reveal the mechanism of flavor stabilization throughout fermentation resulting from the back-addition of CS. PRACTICAL APPLICATION: Roasted cocoa liquor fermented with cocoa sweating (CS) is sensorily similar when fermented for 5 or 7 days and produces cocoa that is sensorily similar to traditionally fermented cocoa in shorter time (5 days vs. 7 days). The addition of CS seems to stabilize 21 flavor compounds throughout fermentation mimicking changes in sensory perception. The back-addition of CS could help standardize cocoa fermentation as indicated by more consistent temperature evolution.

Ginsenosides are the primary active substance in ginseng plants and have a variety of benefits. However, its light and heat stability are weak and easy to decompose. This study used gum arabic (GA) and maltodextrin (MD) as wall materials, and 1% Tween 80 was used as emulsifier. Response surface methodology was used to optimize the preparation process of total saponins in the stems-leaves of Panax notoginseng (SLPNs) (SSLP) microcapsules by spray drying and freeze drying techniques. Under optimal process conditions, the two microcapsules have better solubility and lower moisture content (MC). The color of spray-dried SSLP microcapsules was greener and bluer, and the color was brighter. In morphology, the spray-dried SSLP microcapsules were spherical with a slightly shrunk surface, whereas the freeze-dried ones were lamellar and porous. The two microcapsules have strong stability under different storage conditions and in vitro gastrointestinal digestion simulation. In addition, both microcapsules and free SSLP contained multiple ginsenosides. At the same time, both microcapsules had good free radical scavenging ability. These results indicate that the microencapsulation technology could improve the stability and bioavailability of SSLP, which is expected to provide a reference for the intensive processing of the SLPN. PRACTICAL APPLICATION: After microencapsulation, the stem and leaf extract of Panax notoginseng improved its stability and taste, which laid a foundation for making more nutritious and better tasting food of the stem and leaf of P. notoginseng.

In order to solve the problem of decreasing the accuracy of quantitative prediction of damage of fruits resulting in the size difference of fruits, the spectral correction method based on the size difference of fruits was adopted. To provide richer theoretical knowledge for the quality detection of fruits and the design of damage reduction programs in reality. First, the undamaged spectra of the group of apples with better performance of the model were selected as the reference spectra by analyzing and comparing the modeling results of the prediction models of mechanical parameters with the single fruit diameter groups. The spectral correction coefficient was calculated with the formulas, and the damage spectra of three groups of apples were size-corrected by this coefficient to build the mechanical parameter models. Finally, the corrected spectra were screened for characteristic wavelengths by competitive adaptive reweighting and uninformative variable elimination algorithms. The results of study showed that the correlation coefficients of the prediction set of the models were improved by 2.1%-13% and the root mean square errors were reduced by 16%-51% with the spectrally corrected models compared with the precorrection models. Therefore, the size correction method can be used to eliminate the effect of size difference on the mechanical parameter models to improve the applicability of the quantitative damage prediction models, and it can provide the theoretical guidance to design the loss-reducing protective measures and the agricultural mechanized operation process.

In this study, microcapsules of Lactiplantibacillus plantarum 299V were prepared using an emulsification/internal gelation technique. Loads of the probiotics were condensed to 9.86 ± 0.13 log CFU/g after 24 h fermentation of the microcapsules. Physical characterization revealed that L. plantarum 299V cells were uniformly distributed within the core of the microcapsules, with a mean diameter of 109.81 ± 0.39 µm and a span value of 0.36 ± 0.00, which were comparable to those of the unfermented microcapsules (p > 0.05). The viability of L. plantarum 299V in the fermented microcapsules was 2.08 ± 0.15 log higher than that of free cells at the end of 5 h simulated gastrointestinal digestion (p < 0.05). Oysters were able to accumulate the fermented microcapsules through filter feeding, resulting in a load of probiotics exceeding 6.00 log CFU/g. The presence of L. plantarum 299V-carrying microcapsules in oyster tissues significantly suppressed spoilage-causing bacteria during 11 days refrigeration storage, suggested by the tested parameters, including total psychrotrophic bacteria, H₂S-producing bacteria, and Pseudomonas spp. (p < 0.05). Pathogenic bacteria, including Vibrio parahaemolyticus and Salmonella enterica artificially introduced into oysters, were also significantly suppressed by over 1.00-log within 4 days compared to control samples (p < 0.05). In summary, oysters bioaccumulated with fermented L. plantarum 299V-carrying microcapsules, justified a novel probiotic-carrying product to exsert the health-promoting effect of probiotics. This solution could also enhance the microbial quality and safety of oysters during storage.

This study aimed to investigate the static and dynamic rheological properties of an ultra-processed powdered goat milk beverage containing carboxymethyl cellulose (CMC), guar gum (GG), and xanthan gum (XG), using a mixture design. Fourteen samples were evaluated, in addition to the original beverage. The flow curves classified the fluids as non-Newtonian and characterized all the reconstituted beverages with pseudoplastic behavior, precisely due to the addition of hydrocolloids that increased the viscosity, and the fresh beverage sample showed the behavior of a dilatant fluid. The stress sweep verified the changes in the storage module (G') and the loss module (G″), the G' ranged from 1.97 to 20.36 (Pa) and the G″ ranged from 5.94 to 11.30 (Pa), demonstrating that there was the formation of beverages with elastic and viscous behaviors. The results showed a synergistic effect between the texture improvers, and the formulations with GG identified a greater effect on the tension. The frequency sweep tests showed that the behavior of the samples was that of a weak gel; however, when subjected to a certain frequency, the values of G' exceeded the value of G″, becoming a sample with more elastic characteristics and consequently, presenting the behavior of a stronger gel. Finally, according to the data presented, it is assumed that formulations containing GG and xanthan gum may produce desirable consumer properties for the reconstituted goat milk drink. Samples with a higher concentration of GG exhibited improved rheological performance, characterized by greater consistency, increased resistance to tension, and higher viscosity at low frequencies. PRACTICAL APPLICATION: The powdered goat milk drink is an innovative product that meets the demands of the food industry and consumers by offering a nutritious and sustainable beverage alternative.

The heat and momentum transfer of tomato puree through a concentric-tube heat exchanger over a range of generalized Reynolds number (0.05 < Re < 66.5) was experimentally and numerically analyzed. Thermophysical and rheological properties of tomato puree (12°Brix) were measured from 20 to 60°C. The velocity, pressure, and temperature were calculated using the computational fluid dynamics (CFD) software FLUENT^TM with temperature-dependent transport properties. The thermal operation of the concentric-tube exchanger was satisfactorily predicted using CFD, indicating accurate measurement of tomato puree properties with temperature variations. A concordance was found between the calculated Fanning friction factor and generalized Reynolds with the experimental correlation. A modified Sieder-Tate correlation was established, which allows properly expressing the Nusselt number as a function of the Peclet number. Simple correlations for the mechanical work and the heat transfer rate as a function of the volumetric flow rate were derived. The thermal efficiency was high at low puree flow rates but decreased with higher rates. However, at high flow rates, ceased its decline, instead showing a slight improvement. The analysis confirmed higher heat transfer rates in the concentric-tube heat exchanger compared to a plain tube at low puree flow rates. The results offer valuable insights for assessing diverse operational conditions in dairy, beverage, sauce, and concentrated food industries. Additionally, they also enhance the analysis and design of concentric-tube heat exchangers. PRACTICAL APPLICATION: The knowledge of the rheological and hydrodynamical behavior of fluids in concentric-tube heat exchangers allows to explore a set of different operating conditions to improve the yield and effectiveness on the system heating/cooling design.

The mammary gland, crucial for milk production in mammals, presents challenges for in vitro study due to its complex structure and limited cell lifespan. We addressed this by introducing the SV40 large T antigen into primary mammary epithelial cells (MECs) from sheep, creating an immortalized T-tag MEC line. This line, stable for over 50 passages, maintained typical epithelial cell morphology during long-term culture. Through transcriptome sequencing and validation, we discovered 3833 differentially expressed genes between MECs and T-tag MEC line, encompassing key biological processes and signaling pathways like cell cycle, p53, and cancer. The cell line, expressing MEC markers (KRT8, KRT18, proliferating cell nuclear antigen, SV40, CSN2, and acetyl-CoA carboxylase alpha), proved capable of synthesizing milk fat and protein. Despite its infinite proliferation potential, the T-tag MEC line showed no tumor formation in mice or cell migration in vitro, indicating stability. This development offers a valuable resource for studying MECs in dairy sheep, facilitating the advancement of long-term culture systems and in vitro lactation bioreactors.

Jujube is susceptible to biotic and abiotic adversity stresses resulting in abnormal phenotypic defects. Therefore, abnormal phenotype fruits should be removed during postharvest sorting to increase added value. An improved maximum horizontal diameter linear regression (MHD-LR) method for size grading of jujube prior to detection of abnormal phenotypic defects was developed. The accuracy of the MHD-LR model is 95%, with an error of only 0.95 mm. In addition, a method for detecting abnormal phenotypic defects in jujube was established. It can effectively and accurately classify seven kinds of jujube phenotypes (regular, irregular, wrinkled, moldy, hole-broken, skin-broken, and scarred). The data augmentation method based on linear interpolation can effectively expand the dataset with a variance of only 0.0006. Support vector machine-decision tree (SVMDT), logistic regression, back propagation neural network, and long short-term memory network models were established to classify jujube samples with different phenotypes, with accuracies of 99.57%, 99.00%, 99.14%, and 99.29%, respectively. The results showed that the SVMDT model had higher accuracy and explainability. This research is expected to provide a new method to improve the precise classification of abnormal phenotypic defects in postharvest jujube.