Journal of Food Measurement and Characterization最新文献

Alkalization changes the physicochemical, bioactive, and powder flow properties of cocoa powders, so it is an essential factor affecting the quality of cocoa products. This study investigated the relationship of the alkalization process with physicochemical properties such as color, pH, and bioactive properties such as total phenolic, flavonoid, and antioxidant capacity of cocoa powders. For this purpose, natural cocoa powders were alkalized using sodium hydroxide (NaOH) or potassium carbonate (K₂CO₃), or potassium hydroxide (KOH) solutions at their different concentrations. The browning index, darkness, and pH values increased while the total phenolic content, flavonoid, and antioxidant capacity decreased depending on the type of alkali used. FTIR spectra revealed changes in the stretching vibrations in the molecular structure of alkalized cocoa powders. Even though the alkalization process did not affect the microstructure of cocoa particles visibly, treatment with different alkali agents altered the thermal behavior, compressibility and caused a decrease in the powder flowability.

Efficient and accurate fruit recognition is critical for applications such as automated fruit-picking systems, quality evaluation, and self-checkout services in supermarkets. Existing vision-based methods, primarily leveraging Convolutional Neural Networks (CNNs), often achieve high performance but are hindered by high computational complexity, making real-time deployment on edge devices challenging. Moreover, the diversity and similarity among fruit varieties, along with imbalanced fruit datasets, pose significant obstacles to general-purpose deep learning algorithms. To address these challenges, we propose the Multi-Scale Attention Pyramid Vision Transformer (MSAPVT) alongside an enhanced version of the Fru92 dataset. Our MSAPVT introduces four innovative improvements: attention enhancement, dimension adjustment, multi-scale feature aggregation and loss function improvement. Firstly, the Hybrid Attention Module (HAM) is designed for better refining the multi-level features of the Pyramid Vision Transformer v2 (PVTv2). Secondly, the Dimension Adjustment Layer (DAL) is designed for increasing the weight of the high-level features. Thirdly, the multi-scale feature aggregation strategy is introduced to fuse multi-scale complementary features. Finally, the KL-divergence loss is added for enhancing the difference between multi-scale features. These innovations enable MSAPVT to capture fine-grained details in fruit images, generating highly discriminative representations with slight low model complexity. Our model achieves the best results on the Fru92 and Fru92s datasets, with Top-1 Acc. of 91.40% and 94.29%, and Top-5 Acc. of 98.95% and 99.55%, respectively. In the end, an approachable and efficient fruit classification system based on MSAPVT is devised for potential applications. The improved dataset is available at https://github.com/iamraoyao/MSAPVT-Inference-Demo.

The microenvironmental factors of kiwifruit are constantly changing over long-distance transportation, but there are no reliable methods for monitoring and predicting quality changes. An artificial neural network (ANN) kiwifruit integrated quality dynamic prediction model based on microenvironmental parameters (i.e., temperature, relative humidity, carbon dioxide, oxygen, and ethylene levels) was developed using the correlation between microenvironmental parameters and changes in quality indicators during storage. The results showed that storage at 4 °C effectively delayed weight loss, increase in cell membrane permeability and soluble solids, as well as decrease in firmness, titratable acid content, ascorbic acid content and color (C* and L* values), delayed the onset of respiratory peaks, lowered ethylene release, and preserved kiwifruit freshness compared to 10 °C and 20 °C. The optimized back-propagation (BP) neural network model had a hidden layer neuron count of 10, and the coefficient of determination (R²) between the predicted and measured values was 0.998, with an average error within ± 5%, which was highly accurate in predicting the overall quality changes of kiwifruit during storage and transportation.

The extraction method usually affects the structure and physicochemical properties of the protein. In this paper, Silybum marianum protein was isolated by reverse micelle extraction, and alkaline extraction and acid precipitation. The structure of the proteins was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and SDS-PAGE, and the effects of the extraction method on the physicochemical properties and antioxidant activity of proteins were also analyzed. The results showed that proteins isolated by reverse micelle extraction (SPRME) were dominated by globular and fibrillar proteins with smooth surfaces and intact edges. Compared to the proteins isolated by alkaline extraction and acid precipitation (SPAE), SPRME contained a greater concentration of proteins in the 10–25 kD range. The β-fold contents of SPRME and SPAE were 26.73% ± 0.18% and 37.78% ± 0.74%, and the β-turn contents were 18.90% ± 0.67% and 14.02% ± 0.72%, respectively. The solubility, oil holding property, foaming capacity, emulsification, and emulsification stability of SPRME were higher than those of SPAE. SPRME has a superior antioxidant capacity than SPAE. These results indicate that milk thistle protein extracted by the reverse micelle method has a complete structure and better functional properties.

This study aimed to produce Plantago major seed gum (PMSG) and carboxymethyl cellulose (CMC) antimicrobial nanocomposite film by adding Cerium oxide nanoparticles (CeO₂ NPs) (2.5 and 5%W/W) as reinforcing additive and Fenugreek seed essential oil (FSEO) (4 and 8%W/W) as a bioactive agent. The nanocomposite films were prepared by casting method, and moisture content, moisture absorption, opacity, water vapor permeability (WVP), antimicrobial activity, and antioxidant properties of them were examined. FTIR, FESEM, XRD, and TGA tests were carried out to study the morphology, crystalline structure, and thermal stability of films, respectively. Moreover, mechanical properties, for instance, tensile strength (TS), elongation at break (EB), and thickness of the films, were measured. The results indicated that adding CeO₂ NPs improved the mechanical properties and formed new crystalline structures on the nanocomposite films. The inclusion of 5% CeO₂ NPs and 8% FSEO had a significant reduction in moisture content and moisture absorption (p < 0.05). Besides, FSEO addition did not have a significant effect on the WVP amount (p > 0.05). However, adding CeO₂ NPs and FSEO caused a significant effect on antimicrobial and antioxidant properties, and the highest antimicrobial and antioxidant activities were obtained by the film containing 2.5% CeO₂ NPs and 8% FSEO. The results showed that the TS was decreased by adding FSEO, and it increased by adding CeO₂ NPs, especially at higher concentrations. EB was significantly affected by the addition of CeO₂ NPs and FSEO, EB was enhanced by the addition of FSEO, and was reduced by the addition of CeO₂ NPs. Instrumental analysis FTIR, FESEM, XRD, and TGA tests showed high potential of PMSG/CMC-based nanocomposite reinforced by CeO₂ NPs and FSEO for food packaging technology.

The cacao pod husk (shell), serves as the tough outer layer of the cacao pod, and this by-product of cacao processing is typically disposed of once the cacao beans have been removed. They contain a variety of compounds and can be repurposed to reduce waste and generate added value. This article offers an extensive and in-depth analysis of the possibility of utilizing cacao pod husk (CPH) as an environmentally friendly packaging material. It meticulously investigates the composition, properties, pre-treatment and extraction methods, and versatile uses of CPH. Particularly, this paper extensively examines the physical and barrier properties that are crucial for packaging, highlighting attributes like durability, pliability, and resistance to moisture, and focuses on how these properties can effectively maintain product freshness and enhance the suitability of CPH for different food items. In addition, the article provides a thorough examination of the various ways in which CPH can be utilized, such as in the creation of antimicrobial coatings, the production of paper that can naturally decompose, and its contribution to the advancement of composite materials, delving into the assessment of its environmental impact and presents optimistic prospects for the future of this eco-friendly packaging alternative. This comprehensive and enlightening review is poised to be an invaluable resource for researchers, professionals in the industry, and policymakers who are interested in harnessing the potential of CPH for sustainable packaging, which proposes a wealth of knowledge and practical insights for those seeking environmentally friendly packaging solutions.

Excessive nitrite ((:{text{NO}}_{text{2}}^{-})) addition poses a significant threat to food safety. Thus, it is desirable to construct a selective and dependable electrochemical sensor for the quantitative measurement of (:{text{NO}}_{text{2}}^{-}). In this study, an electrochemical sensor using nitrogen-rich porous carbon (NPC) derived from graphitic carbon nitride (g-C₃N₄) was developed for the quantitative detection of (:{text{NO}}_{text{2}}^{-}). The NPC synthesis involved a two-step process, namely polymerization and carbonization. The carefully designed polymerization method and optimal carbonization condition yielded an NPC material with a relatively high surface area of 593.36 m²·g⁻¹. Notably, NPC nanomaterials exhibited a high nitrogen content of 19.8%, comprising various nitrogen species (pyridinic N, pyrrolic N, and oxidized N) that are fully faradaic-active N species, leading to enhanced electrochemical properties and sensitivity. The calibration plot exhibited linearity within the concentration range of 2-3410 µM, LOD of 0.11 µM, a sensitivity of 11.32 µA·µM^− 1 cm^− 2 and further showed excellent adaptability in real sample analysis. This innovative way of creating electrochemical sensors from nitrogen-rich porous carbon materials broadens the scope of electroanalysis and provides a beneficial means of guaranteeing food safety.

Chlorophyll b quantities of raw (control) and roasted rapeseed samples were specified to be higher than chlorophyll a. Additionally, total phenol, total flavonoid quantities and antioxidant activity (DPPH and FRAP assays) values of roasted powdered and whole rapeseed samples were observed to increase compared to the control. K₂₃₂ and K₂₇₀ values ​​of conventional oven roasted, ground and whole rapeseeds were slightly higher than the results in the microwave. The highest K₂₃₂ value was observed in oil provided from the sample that was powdered and heat treated in conventional oven. The phenolic constituents of ground and whole rapeseeds were partially higher than those of their oils. The dominant fatty acids of the oils extracted from unroasted and roasted rapeseeds were oleic, linoleic, linolenic and palmitic acids in decreasing order. Oleic acid quantities of the oil provided from powdered and whole rapeseeds roasted in microwave and oven were defined as 62.00 and 61.97% to 61.48 and 62.06%, respectively. The main variables of PC1 for rapeseed were dedected as catechin (0.912), coumaric acid (0.840) and ferulic acid (0.733).

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In this study, the role of oven and microwave roasting on the oil, chlorophyll, total phenol, flavonoid contents, antioxidant activities (DPPH and FRAP assays), specific absorbance (K232, K270) values, phenolic profile and fatty acid compositions of rapeseed was revealed

In recent years, fruit pulp products that fully retain the nutritional value and original flavor of fresh fruit have been favored by consumers. This paper investigates the changes in cell wall structure during the enzymatic preparation of Goji berry pulp and the impact of enzymatic treatment on pulp quality. The results showed that, compared to the control group, the yield of pulp after 95 min of enzymatic treatment increased from 74.90 ± 0.64% to 91.30 ± 0.21%, with a reduction in particle size and a 164.7% increase in conductivity. Additionally, the cell wall components of Lycium barbarum were also structurally characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), high performance gel permeation chromatography and ion chromatography. The study revealed that enzymatic hydrolysis disrupted the cell wall structure, resulting in a 66.1% reduction in pectin molecular weight and degradation of the RG-I structure in monosaccharides. These structural changes led to an increase in the nutritional content and antioxidant capacity of Goji berry pulp as the enzyme treatment time was extended. Specifically, after 95 min of enzymatic hydrolysis, the protein and vitamin C content in the pulp increased by 13.79 and 52.17%, respectively, compared to the non-enzymatic pulp. This study underscores the potential of compound enzyme treatment as an effective approach for enhancing the processing and production of Goji berry pulp. It can improve the quality and nutritional value of the pulp to meet consumer demand for high-quality products and offers valuable insights for optimizing pulp processing techniques.

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The present study aims to characterize the nutritional and potential applications of Dioscorea esculenta (Suthni) flour (SF) in comparison to potato flour (PF). Results revealed similarities in mineral content and crystalline structures, while the higher fat content in SF presents potential advantages in mouthfeel and flavor. SF exhibits a notably shorter peak viscosity (506.6 m.Pa) compared to PF (616 m.Pa), indicative of its rapid gelatinization kinetics and making it advantageous in rapid thickening products such as instant sauces or soups. The irregular and agglomerated structure of SF, compared to the uniform oval shape of PF, was revealed by SEM. Similar functional groups were observed in both tubers, as revealed by FTIR. Amino acid profiles highlight distinctions in protein quality, with SF showing higher a glutamic acid content and limited sulfur-containing amino acids and aromatic amino acids. The results indicated that a combination of 60% SF and 40% Refined Wheat Flour (RWF) had the highest acceptability. As the proportion of PF increased, a progressive reduction in hardness was observed. The addition of SF (40%) exhibited increased hardness (2971.95 g) and adhesiveness (89.35 g.s), contributing to higher gumminess (544.36 g) and chewiness (398.22 g). The cookies made with SF had higher L*, b*, and lower a* values. Based on these findings, SF shows promise as a substitute for RWF and as an ingredient in functional foods and baked goods, which could increase the commercial value of underutilized tubers like potato and yam.

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