Journal of the Science of Food and Agriculture最新文献

Background: This research aimed to enhance the functional value of dietary fiber from broccoli leaves using supercritical fluid technology. By optimizing pressure, temperature, and time parameters through response surface methodology, the study sought to improve the bioactive properties of the fiber and develop a predictive model for its chemical composition and functional properties.

Results: Structural analysis indicated that modified samples had a higher concentration of oligosaccharides than control samples did, with significant increases in galacturonic acid and neutral sugars after supercritical fluid technology treatment, highlighting enhanced pectin release due to cell wall degradation. Functional properties, such as water solubility, glucose absorption capacity, and antioxidant activity, improved significantly under optimized conditions (191 bar, 40 °C, 1 h). Multivariate analysis confirmed the effectiveness of supercritical fluid technology in enhancing the dietary fiber properties, achieving a global desirability value of 0.805.

Conclusion: These results underscore the potential of supercritical technology for valorizing broccoli leaf by-products, enhancing their health-promoting characteristics and functional applications in the food industry. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Background: Lignin peroxidase is closely related to agriculture and food as it improves the quality of feedstuffs, facilitates the degradation of lignin in agricultural wastes, and degrades azo dyes that have similar complex structures to lignin. However, the current status of homologous or heterologous expression of lignin peroxidase is unsatisfactory and needs to be modified with the help of immobilization and directed evolution to maximize its potential. Directed evolution technology is an effective strategy for designing and improving enzyme characteristics, and Bacillus subtilis spore surface display technology is an efficient method for preparing immobilized enzymes.

Results: A colorimetric dye decolorization assay using Congo red as a substrate was developed and optimized for high-throughput screening of spore surface display in a 96-well plate. After two rounds of screening, a superior mutant strain was selected from 2700 mutants. Its highest catalytic activity was 196.36%. The amino acid substitution sites were identified as N120D and I242T.

Conclusion: The mechanism for the enhanced catalytic activity was explained using protein modeling and functional analysis software. This study provides insights into the rational design of lignin peroxidase and its application in food and agriculture. © 2024 Society of Chemical Industry.

Background: The content of 2-acetyl-1-pyrroline (2-AP) directly affects the aroma and taste of rice. Δ1-Pyrroline and methylglyoxal are the precursors of 2-AP synthesis, and β-glucosidase plays an important role in the synthesis of methylglyoxal. In this study, β-glucosidase gene cloned from Pyrococcus furiosus was molecularly modified to obtain the high-temperature-resistant β-glucosidase gene 371-β-glucosidase (T371A), which was transformed into kitaake varieties (Oryza sativa L. subsp. japonica) by Agrobacterium-mediated transformation method, and transgenic rice with heterologous expression of T371A was obtained. Experiments were conducted in transgenic rice to investigate whether this gene had an effect on the synthesis of 2-AP.

Results: Under the optimum reaction temperature of 50°C and cooking temperature of 100°C, the enzyme activity of β-glucosidase in transgenic rice seeds was prominently increased by 260-280% and 419-426% over that of the control, respectively. The content of 2-AP in transgenic rice seeds significantly increased by 75-105% under normal temperature and high-temperature cooking conditions compared with the control. It was also found that transgenic rice increased the content of methylglyoxal and decreased the expression of betaine aldehyde dehydrogenase (BADH2).

Conclusion: The high-temperature-tolerant β-glucosidase gene obtained in this study provides an innovative technical strategy for molecular breeding of high-edible aroma crops and has wide application potential. © 2024 Society of Chemical Industry.

Background: The black goji berry (Lycium ruthenicum Murr.) is known for its abundance of high-quality natural antioxidants, particularly anthocyanins. Black goji berry anthocyanins (BGA) are receiving increasing attention because of their high safety and beneficial biological activities. Studies have shown that oxidative stress is a key factor affecting aging, whereas antioxidants are critical preventive and delaying strategies.

Results: In the present study, we investigated the potential anti-aging effects and mechanism of BGA using the Caenorhabditis elegans model. We found that BGA prolonged the mean lifespan of nematodes and improve their healthspan, including locomotion, pharyngeal pumping rate and stress resistance. Subsequently, we observed a significant decrease in reactive oxygen species and malondialdehyde levels in nematodes after administering BGA. Moreover, BGA enhanced the activities of the antioxidant enzymes superoxide dismutase and catalase, and elevated the glutathione disulfide/glutathione ratio. We confirmed that BGA exerted excellent antioxidative stress activity in nematodes, which may contribute substantially to its anti-aging effects. The health benefits of BGA in C. elegans might be closely related to petunidin-3-O-glucoside, the most abundant anthocyanin in BGA. Further mechanistic investigation revealed that the JNK-1 and DAF-16/FOXO pathways, rather than the calorie restriction pathway, were responsible for the antioxidant stress and life-prolonging effects of BGA in nematodes.

Conclusion: Our research provides a theoretical foundation for studying the anti-aging effect of BGA and a basis for developing black goji berry and its anthocyanins as functional foods with anti-aging and antioxidative stress benefits. © 2024 Society of Chemical Industry.

Background: Pea protein isolate (PPI) is gaining increasing popularity in the food industry. It provides a diverse range of health benefits, such as hypoallergenic and gluten-free characteristics. However, the functional performance of PPI is hindered by its low solubility and poor stability. Therefore, in this article, PPI and dextran (DX) of different molecular weights were grafted to investigate the effects of grafting DX with different molecular weights on the interface properties and antioxidant properties of PPI. Additionally, the stability and digestive properties of the glycated PPI nanoemulsion system were explored.

Results: The result showed that the grafting degree of PPI-DX conjugates (PPI-DC) decreased with an increase in the molecular weight of DX. Surface hydrophobicity, antioxidant activity and solubility of PPI-DC were significantly improved after grafting compared with PPI and PPI-DX mixtures (PPI-DM). Astaxanthin-loaded emulsions stabilized by grafted conjugates had smaller droplets and higher astaxanthin encapsulation rate compared to PPI emulsions. In vitro digestion demonstrated that the bioavailability of PPI-DC emulsions was higher than of PPI emulsion. Furthermore, after 24 days of storage, retention rate of astaxanthin-loaded emulsions prepared by conjugates remained above 70%, surpassing that of PPI emulsion.

Conclusion: These results indicated that DX grafting can improve the emulsion properties of PPI. In addition, the DX with a molecular weight of 5 kDa showed the most significant improvement. This study contributes to the advancement of natural emulsifiers by modifying PPI through glycation, and furnishes a valuable reference for its utilization in functional foods. © 2024 Society of Chemical Industry.

Background: The identification of adulterated sweet potato vermicelli faces significant challenges, seriously hindering the development of the vermicelli industry. Herein, we investigate effects of energy-gathered ultrasound (EGU) and energy-divergent ultrasound (EDU) (30, 40 and 50 W  L^-1) on structure, DNA extraction and adulterated quantification of sweet potato vermicelli and its starch, thereby exploring their potential in adulteration of sweet potato vermicelli.

Results: EGU-assisted modified cetyltrimethylammonium bromide (CTAB) protocol with β-mercaptoethanol significantly improved DNA extraction from sweet potato vermicelli (223.7-249.2 ng μL^-1) and its starch (133.4-186.4 ng μL^-1), followed by EDU-assisted DNA extraction from sweet potato vermicelli (115.1-209.3 ng μL^-1) and its starch (33.4-61.0 ng μL^-1). Both EGU and EDU treatments resulted in the destruction of microstructure and crystalline structure, as well as changes in pasting and thermal properties of sweet potato vermicelli and its starch. Real-time polymerase chain reaction (PCR) amplification results revealed that EGU and EDU enhanced the efficiency of DNA amplification, and EDU showed smaller cycle threshold (C_t) values than EGU. In addition, EDU-assisted CTAB protocol combined with real-time PCR could detect levels of less than 1% of cassava and maize starches in sweet potato vermicelli.

Conclusion: EDU-assisted CTAB protocol combined with real-time PCR shows promise as a sensitive and reliable analytical tool for vermicelli adulteration. © 2024 Society of Chemical Industry.

Each year, approximately million tons of waste is generated from eggshells disposed of in landfills. This waste is challenging to manage because of the odor and microbiological development. However, eggshells have potential applications as a solid byproduct. They can be modified and used in various industries such as metal, polymer and ceramic composites, in the production of biodiesel, heavy metal absorption from wastewater, and even as a biomaterial to substitute bone tissues. Furthermore, eggshells can be used as a cheap adsorbent for the treatment of contaminated waterways. They are also a great source of calcium and fertilizer for plants, animals and humans. Chicken eggshells can even be used as a catalyst for converting waste frying oil into biofuel. This review highlights the challenges and opportunities of eggshell waste valorization in the food industry. © 2024 Society of Chemical Industry.

Background: Intelligent identification and precise plucking are the keys to intelligent tea harvesting robots, which are currently of increasing significance. Aiming at plucking tender leaves for high-quality green tea production, in this study, a tender leaf identification algorithm and a mechanically perceptible plucking finger have been proposed.

Results: Based on the segmentation algorithm and color features, the tender leaf identification algorithm shows an average identification accuracy of over 92.8%. The mechanically perceptible plucking finger plucks tender leaves in a way that a human hand does, aiming to maintain the high quality of tea products. Though finite element analysis, we determine the ideal size of grippers and the location of strain gauge attachment on a gripper to enable the employment of feedback control of desired gripping force. As revealed in our experiments, the success rate of tender leaf plucking reaches 92.5%, demonstrating the effectiveness of our design.

Conclusion: The results show that the tender leaf identification algorithm and the mechanically perceptible plucking finger are effective for identification of tender leaves and plucking, providing a foundation for the development of an intelligent tender leaf plucking robot. © 2024 Society of Chemical Industry.

Background: Flavonoids, found in common vegetables and fruits, have health benefits that are often limited by their low bioavailability. Excipient emulsions provide an effective strategy to overcome these obstacles. However, the nature of the emulsifier used to formulate excipient emulsions and the chemical structure of the flavonoids both affect the bioaccessibility of the flavonoids.

Results: The purpose of this study was to investigate the impact of the interfacial properties of excipient emulsions on the in vitro gastrointestinal fate of representative structural flavonoids (quercetin, kaempferol, and apigenin) through the INFOGEST method. Tween 80 (TW80) (a nonionic surfactant) was more effective at reducing the oil-water interfacial tension than whey protein isolate (WPI) (a protein-based emulsifier) or octenyl succinic anhydride (OSA)-modified starch (MS) (a polysaccharide-based emulsifier). Moreover, TW80 created excipient emulsions with smaller oil droplets, which were more resistant to oral and gastric conditions. The WPI-emulsions underwent severe flocculation in the gastric phase, leading to an appreciable increase in particle size (from 220 to 3000 nm). The TW80-coated oil droplets were more digestible than WPI- or MS-coated ones. This was attributed to the larger lipid surface area for lipase attachment. The bioaccessibility of quercetin, kaempferol, and apigenin was also affected by emulsifiers: TW 80 (25% to 45%) > WPI (14% to 29%) ≈ MS (15% to 25%). Flavonoid bioaccessibility appeared to be related to their molecular properties.

Conclusion: This study provides guidance for the design of effective excipient emulsions to enhance the bioavailability of flavonoids. © 2024 Society of Chemical Industry.

Background: Soy protein isolate (SPI) gels formed using a single coagulant often have poor water-holding capacity (WHC) and low hardness, making them fragile and unsuitable for transportation and storage. Adding compound coagulants or polysaccharides can improve the gelation properties of SPI gels induced by gluconolactone (GDL). This study explores the impact of oxidized konjac glucomannan (OKGM) on the physicochemical and structural properties of GDL-induced SPI gels, with the aim of evaluating the potential of OKGM for enhancing the overall quality and stability of these gels.

Results: In this study, the composite gels demonstrated a significant increase in whiteness (69.02% to 70.59%) compared with the SPI gel (67.41%). Key physicochemical properties, such as water-holding capacity (WHC), textural characteristics, viscoelasticity, and thermal stability, were notably improved. Scanning electron microscopy (SEM) revealed a reduction in the average pore diameter of the composite gels from 70.57 ± 4.13 μm to 37.19 ± 0.24 μm when the oxidation degree of OKGM was kept at or below 60 min, contributing to a more compact and orderly microstructure. Enhanced hydrophobic and electrostatic interactions within the composite gels also accelerated the gelation process, shortening the gelation time from 15.77 ± 0.37 min to 12.45 ± 0.18 min.

Conclusion: The results demonstrate that OKGM acts effectively as a gel enhancer, improving the physicochemical and structural properties of SPI gels significantly. © 2024 Society of Chemical Industry.