Journal of Food Science最新文献

The walnut cracking process is the most critical and delicate step for achieving high-quality kernels. The traditional method for cracking (manually) is labor-intensive, time-consuming, and tedious. The existing cracking approaches are low production efficiency and serious walnut kernel breakage. Increasing cracking efficiency with minimum kernel breakage has been a challenging issue in the preliminary processing of walnuts. Therefore, this study develops an innovative walnut cracker with self-grading and multi-station extrusion, combined with theoretical investigation and experiment verification. First, a statistical analysis of walnut physical properties was conducted, including dimensions, shell thickness as well as shape characteristics. The mechanical properties of walnut cracking were examined by a series of experiments. Based on mechanical theory, a grading mechanism was designed for preliminary processing before walnut cracking. Then a shaftless screw conveying mechanism and an extrusion cracking mechanism were developed. To evaluate the cracker's performance, a comprehensive examination was carried out. The experiments yielded impressive results, with a grading rate of 87.3%, a shell-breaking rate of 91.50%, and a kernel-exposed rate of 84.72%. These outcomes signify a substantial improvement in production efficiency while minimizing kernel breakage. The developed walnut cracker plays a crucial role in walnut processing and kernel extraction, thereby elevating economic value. PRACTICAL APPLICATION: A self-grading multi-station extrusion walnut cracker is developed, which includes a grading mechanism with a shaftless screw conveyor and a grid-type trommel screen for conveying and classifying walnuts. This cracker can adapt to different walnut varieties by changing the gap-adjusting guide to control the breaking gap. Compared to similar extrusion-type walnut crackers, the developed cracker not only incorporates preliminary classification but also exhibits superior performance. HIGHLIGHTS: A novel multi-station extrusion mechanism for walnuts cracking is developed. The cracker can accommodate various walnut sizes for self-grading and screening. The design with semi-arc plates converts extrusion force into alternating stress. The shell-breaking rate and kernel-exposed rate achieves 91.50% and 84.72%.

Fermented walnut meal (FW) has antifungal activity against Penicillium victoriae, a fungus responsible for Rosa roxbughii Tratt spoilage. This study characterized and applied ultrasonic-assisted antifungal film loaded with FW to preserve R. roxbughii Tratt during near-freezing temperature (NFT). Results showed that O₂ and CO₂ transmission rates decreased by 80.02% and 29.05%, respectively, and antimicrobial properties were improved with ultrasound at 560 W for 5 min and 1% FW. Fourier transform infrared spectroscopy and X-ray diffraction results revealed ultrasound improved hydrogen bonds and inductive effect via ─NH, ─OH, and C═O bonds. The addition of FW led to the formation of CMCS-GL-FW polymer via C═O bond. Thermogravimetric analysis and transmission electron microscope results demonstrated thermal degradation process was decomposed by ultrasound, and the internal structure of P. victoriae was accelerated by the addition of FW. Compared to the U-CMCS/GL group, the vitamin C content, peroxidase, and catalase activities of U-CMCS/GL/FW were enhanced by 4.24%, 8.52%, and 14.3% during NFT (-0.8 to -0.4°C), respectively. Particularly, the fungal count of the U-CMCS/GL/FW group did not exceed 10⁵ CFU g^-1 at the end of storage, and the relative abundance of P. victoriae decreased to 0.007%. Our findings provide an effective route for agricultural waste as natural antifungal compounds in the active packaging industry. PRACTICAL APPLICATION: In this study, the barrier and antimicrobial properties of film were successfully improved by ultrasonic treatment and loaded fermented walnut meal. The ultrasonic-assisted antifungal film loaded with fermented walnut meal effectively delayed the degradation of nutrients and reduced microbial invasion of Rosa roxburghii Tratt. These results provide a theoretical basis for the application of agricultural waste in the food packaging industry.

Consumers' familiarity with foods influences their expectations and experiences upon consumption. Familiarity has mostly been assessed using perceived familiarity when studying single foods. However, foods are often combined to create dishes, complex compositions eaten at various mealtimes. Hence, this paper aimed to study if and how the level of consumers' dish familiarity shapes their motives and preferred contexts for home cooking and consuming three dishes: one traditional dish, one adopted ethnic dish, and one mainly unavailable and unknown ethnic dish. First, we describe the operationalization of familiarity into the qualitative "consumer's dish familiarity index" (CDFI) used to determine participants' familiarity level to the dishes. CDFI includes four indicators (perceived availability, consumer's knowledge, preparation, and consumption). In-depth interviews (n = 27) were conducted with Dutch and Chilean women, as the countries have contrasting levels of immigration and globalization, which are expected to shape their inhabitants' familiarity level with ethnic dishes. Most experienced consumers (high familiarity) mentioned more dishes and individual-related motives to prepare and consume a traditional or an adopted ethnic dish. Social- and individual-related motives were salient when a dish was unknown and/or not previously consumed. Consumers' familiarity level also guided their preferred social context and location when consuming the dishes. A dish barely available will likely be first consumed in a restaurant to try a new dish that is perceived as appetizing to eat. Results showed that convenience, wanting to eat comfort foods, and showing affection to others are important motivators to facilitate the adoption of dishes to be home cooked. PRACTICAL APPLICATION: This paper provides a novel approach to assess consumer familiarity to dishes. The qualitative consumer's dish familiarity index (CDFI) can be used in future investigations to assess and classify consumers into different dish familiarity levels by using four indicators. The outcomes of this study suggest consumers' familiarity level could serve as a reference for designing and/or improving (ethnic) foods and creating marketing campaigns to introduce them into (foreign) countries.

In this study, garlic extract (GE) was assessed as a potential additive in chitosan/starch (Ch/De) coatings, focusing on phenolic and flavonoid content analyses and antibacterial properties. Using response surface methodology approach, an optimization method was employed to achieve the optimal antibacterial formulation, with Ch, De, and GE identified as key variables in the Design of Experiment. Fourier transform infrared spectroscopy and X-ray diffraction analyses elucidated interactions among these primary components within the films, while thermogravimetric analysis confirmed the enhanced thermal stability of GE-coated film formulations (Ch/De/GE). The Ch/De/GE exhibited antibacterial efficacy against Escherichia coli (ATCC 25922) with an inhibition zone of 7.2 mm at optimized concentrations of 2% w/v Ch, 1.5% w/v starch, and 0.5% v/v GE. In silico molecular docking studies provided insights into GE's inhibitory role as an antibacterial agent. Evaluation of green and yellow bell peppers (Capsicum annuum) over 18 days showed that coated peppers maintained better visual appearance and mass stability, with a weight loss decrease of 40.54%-48.96%, compared to uncoated ones. Additionally, the Ch/De/GE coating effectively inhibited bacterial growth, reducing it by 1-1.23 log CFU, during the storage period. In conclusion, the Ch/De/GE coating effectively extends the shelf-life of bell peppers and maintains their quality, demonstrating its potential for use in food packaging to preserve perishable items. PRACTICAL APPLICATION: The optimized chitosan/starch/garlic extract (Ch/De/GE) film developed in this study shows promising potential for application in the food packaging industry, particularly in extending the shelf life of perishable items like bell peppers. Its enhanced antibacterial properties, along with its ability to maintain visual appearance and reduce weight loss, make it an effective natural preservative that could replace synthetic additives in food packaging. By incorporating this biodegradable film into packaging solutions, producers can offer safer, more sustainable products that meet consumer demand for natural and environmentally friendly options.

Abstrac: Female adult Eupolyphaga sinensis Walker (FAESW) has traditionally been a food source in Southeast Asian countries such as China and India, due to its rich nutritional content. However, the nutritional value of male adults (MAESW) and its molts (MESW) has hardly been reported. Therefore, this study aims to explore the potential application of MAESW and MESW in food by investigating and comparing their nutritional composition (i.e., protein, amino acids, fatty acids, and essential elements) with traditional sources of nutrition. The protein content of MAESW and MESW was 66.10 ± 0.49% and 59.86 ± 6.07%, respectively, and the highest energy content (462.26 ± 1.28 kcal/100 g) was observed for MAESW. Eight essential amino acids were determined, of which the males and MESW were found to have higher contents than those of FAESW (p < 0.05). Oleic and linoleic acid contents were higher in the adults than nymphs. Moreover, MESW was predominant in calcium (6770.84 mg/kg), whereas MAESW was rich in iron (556.12 mg/kg). Likened to chicken, the protein, amino acid, fatty acid, and mineral contents of ESW were higher. The volatiles of ESW were related to hexaldehyde, benzaldehyde, acetic acid, and butyric acid. This study provides a better understanding of the chemical composition of ESWs during their growth cycle and helps optimize information on edible insects, promoting their use as a potential food source for humans.

Practical application: As a kind of edible insect, the utilization of adult male Eupolyphaga sinensis Walker (ESW) and its molt is very low at present. Therefore, this study examined the nutrients and volatile substances of ESW (at different growth stages) and molt, which provided a theoretical basis for the subsequent development and utilization of ESW.

Microencapsulation has the potential to address the stability issues associated with vitamin A. This study examined the effectiveness of emulsifying a saponin-chitosan polyelectrolyte complex to encapsulate vitamin A. Utilizing response surface methodology (RSM), the effects of the chitosan, saponin, and vitamin A contents on various response variables were measured to optimize the formulation. The optimized emulsion was characterized through fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), storage stability, and release profile. Fluorescence microscopy showed that vitamin A was evenly distributed throughout the optimized emulsion. The polyelectrolyte complex and vitamin A were shown to interact hydrophobically and electrostatically by FTIR analysis. The DSC results verified the effective encapsulation and showed that vitamin A heat stability had been enhanced. Study on storage stability demonstrated that during a 2-month storage period, the encapsulated vitamin A remained stable. Moreover, vitamin A was significantly released from the encapsulated form at pH 1.2, based on release assays. In conclusion, saponin-chitosan polyelectrolyte coating proved to be a potentially useful new material for the stability and applications of vitamin A in a range of formulations.

Hemp seed oil (HSO) is an edible oil low in saturated fat and rich in polyunsaturated fatty acids (PUFAs) such as omega-6 and omega-3 fatty acids. When they are in contact with oxygen in the air, PUFAs are easily oxidized even at room temperature due to the multiple double bonds that facilitate the formation of reactive radicals when exposed to air. This study aimed to evaluate the oxidation of HSO under different conditions and to examine the encapsulation of HSO with zein as a new method to prevent its oxidation. Peak time of weight gain monitored with thermogravimetric analysis and oxidation products detected with high-performance liquid chromatography were used to determine the oxidation of fatty acids and HSO. It was found that the thermal decomposition of fatty acids prevailed over autoxidation beyond a certain temperature (at about 100-140°C). Encapsulating HSO into zein microcapsules, which isolates oil droplets from contact with oxygen in the air, effectively prevented its oxidation. The induction period of HSO oxidation was delayed by 7.3-9.3 times with the zein-to-HSO ratio of 0.5-1.25. In contrast, 0.5% (w/w) α-tocopherol could prolong the induction period up to 2.5 times indicating that the encapsulation method was much more effective than α-tocopherol in preventing the oxidation of HSO. This method may also be applied for other oils susceptible to oxidation such as omega-3 oils. PRACTICAL APPLICATION: This research compares the effects of three schemes that stabilize hemp seed oil from oxidation: (1) lowering temperature to slow down the oxidation reaction, (2) adding antioxidant to deactivate the initiation of oxidation reaction, and (3) encapsulating oil droplets into protein microcapsules to keep the oil from contact with oxygen. The experimental result showed the encapsulation of oils in protein microcapsules is more effective than the other two. The stabilization approaches applied to hemp seed oil can also be applied to other edible oils that are unstable.

Grape pomace (GP) is a waste product of the winemaking process and has been proposed as a nutritionally beneficial ingredient, as it contains phenolic compounds, dietary fiber, and antioxidant activity. It can be a polarizing ingredient due to its flavor components. Familiarity has been found to influence consumers' preferences and sensory perception of food. A sensory test was conducted to evaluate the acceptance, sensory perception, and emotional response to pasta sauces containing GP (3% [3GP], 6% [6GP], 9% [9GP] by volume and control without GP addition). The sensory trials included wine consumers (n = 44) and nonconsumers of wine (n = 58) to determine how consumers' familiarity with the flavor properties of GP influenced their perception of the pasta sauce. Overall, the addition of GP decreased the liking scores of the GP-containing sauces, but the wine consumers' hedonic scores for the control, 3GP, and 9GP were significantly higher than the nonconsumers. Both consumer groups identified that the samples with a higher amount of GP addition were associated with sour, bitter, astringency, grainy, and gritty attributes. However, the wine consumers used more positive emotions to describe their emotional response to the GP-containing samples. The study identified that GP led to off-flavors and textures in the pasta sauces. PRACTICAL APPLICATION: GP is currently a waste product, but it has many nutritional benefits. Consumers are increasingly looking for nutritional benefits from their food. When incorporated into pasta sauces, GP decreased the acceptance of the pasta sauce and negatively impacted the flavor and texture. Familiarity has been found to impact consumer acceptance, and wine consumers had a more positive emotional response and higher hedonic scores in response to the GP-containing pasta sauce than nonconsumers of wine.

Sea buckthorn has lipid-lowering properties and is widely used in the development of functional foods. In this study, a probiotic (Lactobacillus plantarum, Lp10211) with cholesterol-lowering potential and acid and bile salt resistant was screened for the fermentation of sea buckthorn juice. Changes in the active ingredients, such as sugars and phenolics, before and after fermentation, as well as their in vitro lipid-lowering activities, were compared. The contents of reducing and total sugars decreased substantially after fermentation. Lp10211 primarily utilized fructose for growth and reproduction, with a utilization rate of 76.9%. The phenolic compound content of sea buckthorn juice increased by 37.06% after fermentation and protected the phenolic components from degradation (protocatechuic and p-coumaric acids) and produced new polyphenol (shikimic acid). Enhanced inhibition of pancreatic lipase activity (95.42%) and cholesterol micellar solubility (59.15%) was evident. The antioxidant properties of the fermentation broth were improved. Notably, Lp10211 preserved the color and reversed browning in sea buckthorn juice. The collective findings indicate that fermentation of sea buckthorn juice by Lp10211 may enhance the functional components and lipid-lowering activity of sea buckthorn, which may provide a new approach for the development of lipid-lowering foods.

Most existing studies have focused on identifying the origin of species with protected geographical indications while neglecting to determine the proximate geographical origin of different species. In this study, we investigated the feasibility of using near- and mid-infrared spectroscopy to identify the origin of 156 Polygonatum kingianum samples from six regions in Yunnan, China. In this work, spectral images of different modes reveal more information about the P. kingianum. Comparing the performance of traditional machine learning models according to single spectrum and data fusion, the middle-level data fusion-principal component model has the best performance, and its sensitivity, specificity, and accuracy are all 1, and the model has the least number of variables. The residual convolutional neural network (ResNet) model constructed in the 1050-850 cm^-1 band confirms that fewer variables are beneficial in improving the accuracy of the model. In conclusion, this study verifies the feasibility of the proposed strategy and establishes a practical model to determine the source of P. kingianum.