Journal of Food Science最新文献

Olive pomace (OP) waste, produced in large quantities, contains significant amounts of cellulose and fibers, making it a valuable resource for developing reinforcing ingredients in biodegradable packaging materials. This study aimed to produce nanofibers from OP using enzymatic hydrolysis with hemicellulases and cellulases, and to incorporate these nanofibers into starch films as a reinforcing agent. Cellulose nanofibers (CNFs) were prepared by alkaline pretreatment followed by enzymatic hydrolysis (with hemicellulases and cellulases) from olive pomace and applied as reinforcement in starch films in concentrations of 0.5%-5% (w/v). The nanofibers were analyzed according to composition, structural, and thermal properties. The nanofibers' suspension presented a cloudy and white color in aqueous suspension, the X-ray diffraction (XRD) analysis showed the increase of crystallinity, and the fibers' range was no wider than 100 nm (according to Scherer equation). The composition analysis showed the decrease of carbonyl groups of hemicellulose and lignin. The starch films presented a homogenous surface. The solubility from these biodegradable films significantly reduced after the incorporation of CNF, and the nanomaterial's presence improved the degradation temperature (from 310°C to 322°C) and the mechanical resistance because the tension of rupture increased from 3.79 to 6.21 MPa. PRACTICAL APPLICATION: The utilization of waste from the olive pomace for cellulose nanofiber production holds promise, given the nanofibers' ability to readily integrate into various materials, including starches used in biodegradable film production. Within these matrices, nanofibers act as structure reinforcers and significantly reduce the solubility of films. Although biodegradable films ensure the shelf life, safety, and quality of food, their properties currently do not match those of traditional petroleum-based materials at an industrial scale, indicating a need for further enhancement.

In this study, a novel active film was developed by employing ε-polylysine (ε-PL) as a filler in pullulan/curdlan (P/CD) composite film (P/CD/ε-PL). The results showed that the structure of P/CD films was more uniform and denser compared to pullulan films, due to the good compatibility and intermolecular interaction between them. Among P/CD films, P/CD 6:1 film showed improved hydrophobicity, mechanical and barrier properties, and thermal stability, thereby selecting it for further use. Thereafter, the addition of ε-PL further enhanced the structural and physicochemical properties of prepared P/CD/ε-PL composite films, especially for P/CD/2.5%ε-PL composite film. It exhibited improved ultraviolet barrier (about 80% at 200-400 nm), antibacterial activity (>90% against Staphylococcus aureus and Escherichia coli), and anti-fog properties (clearly visible and transparent background). Furthermore, P/CD/2.5%ε-PL composite film exerted its preservation effect on fresh-cut peppers and kiwis during storage, delaying the softening, consumption of soluble solids, and deterioration. Therefore, the developed P/CD/2.5%ε-PL composite film provided promising applications of active packing film. Practical Application: Fresh-cut fruits and vegetables are prone to deteriorate during storage, and active packaging films play a crucial role in retaining their quality. This study was conducted to prepare a composite film by blending pullulan, curdlan, and ε-PL and explore its structural, physicochemical, and functional properties, further verifying the preservation effect on fresh-cut peppers and kiwis. Compared to polyethylene film, the P/CD/2.5%ε-PL composite film delayed the softening, consumption of soluble solids, and deterioration of fresh-cut peppers and kiwis during storage. It provides a new perspective on the preservation of fresh-cut fruits and vegetables.

This study investigated the quality changes of quick-frozen wet rice flour before and after freeze-thaw cycles. As the freeze-thaw cycle was prolonged, the water mobility of quick-frozen wet rice flour decreased and the pore size and porosity of the microstructure increased. As a result, the hardness, cooking loss, water absorption, and water precipitation of the rice flour increased, while the sensory score and viscosity decreased. Correlation analysis showed that porosity was positively correlated with the hardness and water absorption of rice flour, and negatively correlated with structural properties such as shearing work and resilience. Water absorption and water precipitation rate were positively related to cooking loss. Thus, moisture migration in rice flour induced microstructural changes to cause alterations in texture, cooking, and sensory properties. Interestingly, quick-frozen wet rice flour still possessed good texture, cooking, and sensory qualities after two freeze-thaw cycles. This study laid the foundation for the development of high-quality quick-frozen wet rice flour.

This study aimed to develop microcapsules with wheat gluten-coated oil droplets to enhance the oxidation stability and control the digestibility of flaxseed oil. The microcapsules were fabricated using a three-step procedure: (i) flaxseed oil was homogenized with an alkaline gluten solution to form oil-in-water emulsions containing small gluten-coated oil droplets (320-400 nm); (ii) the pH of these emulsions was then neutralized to facilitate the deposition of gluten around the oil droplets, thereby forming a thick layer; (iii) a flaxseed oil microcapsule powder was then prepared by spray drying. During the microcapsule formation, intermolecular interactions, including hydrophobic interactions and hydrogen bonds, were involved in the coacervation of gluten at the emulsion surface. The resultant microcapsules with a multiple-core structure had external diameters of 4-26 µm and encapsulation efficiencies of 90%-94%. The microencapsulated oil powders contained a relatively high flaxseed oil content (60%-80%). Among them, the sample with 60% oil content demonstrated the best stability in resisting oil droplet coalescence; thus, it exhibited a higher lipolysis rate and extent during simulated gastrointestinal digestion. A 30-day accelerated storage study showed that encapsulation of the flaxseed oil improved its resistance to oxidation. These findings suggest that the pH-deposition method can successfully produce microencapsulated polyunsaturated lipids using all plant-derived ingredients, which may facilitate their use in new plant-based foods through a green and sustainable approach.

In this study, the high-moisture meat analogs (HmMAs) were developed by incorporating defatted sesame cake powder (DSP) in soy protein isolate (SyPI). The quality attributes of HmMA like visual appearance, specific mechanical energy (SME), mass flow rate (MFR), phenolic profile, textural and rheological properties were assessed after varying DSP concentrations (0%, 20%, 40%, and 60% w/w) and feed moisture (FM) levels (55% and 60%). The HmMA₁ (derived solely from SyPI) exhibited higher hardness, chewiness, gumminess, cohesiveness, and springiness. The HmMA prepared from SyPI-DSP blends (HmMA_2-8) demonstrated significant improvements in nutritional composition, and their visual characteristics indicated noticeable anisotropy. The interaction between SyPI and DSP influenced the quality of HmMA. The higher DSP concentration led to higher MFR and deeper curvatures of U-shaped structures, whereas lower SMS, textural and rheological properties. The DSP incorporation and 55% FM adjustments allowed mimicking meat cuts with thick fiber, influenced color, and proved advantageous in developing white meat analogs with higher free phenolics. The findings of the study suggest avenues for exploring DSP at a suitable level in SyPI for the development of better quality meat analogs.

The impact of Lacticaseibacillus paracasei NWAFU334 and Limosilactobacillus fermentum NWAFU0035 on the amelioration of liver function, oxidative stress reduction, and lipid metabolism modulation in mice subjected to an obesity-inducing high-fat diet (HFD) model was investigated. L. paracasei NWAFU334 and L. fermentum NWAFU0035 supplementations over 12 weeks have been shown to have numerous beneficial effects in mice with induced obesity. These effects comprise the restoration of liver function and the reduction of oxidative stress within the liver. Furthermore, the supplementation led to a decreased content of fat accumulation in the liver, mitigation of the expression of inflammatory cytokines in the liver and colon, and a decrease in the expression levels of tight-junction proteins, for example, claudin-1, PPARγ, occludin, and ZO-1. Additionally, a notable improvement in the colonic expression proteins, including IL-6, TNF-α, IL-1β, Muc-2, Muc-3, Zo-1, claudin-1, and occludin. These proposed strains considerably decreased proinflammatory cytokines and influenced the regulation of lipid metabolism in the liver. These findings indicate that the potential mechanisms, primarily the impact of L. paracasei NWAFU334 and L. fermentum NWAFU0035 on obesity-induced liver function in mice, involve two regulated pathways: downregulation of lipogenesis and upregulation of gene expression related to fatty acid oxidation and lipolysis. In other words, these probiotic bacterial strains might be beneficial in reducing fat production and increasing fat breakdown in the liver. They may serve as effective therapeutic supplements for alleviating abnormalities induced by an HFD.

Coconut endosperm residue is an abundant and low-cost resource of dietary fiber, but the low soluble fiber content limits its functional properties and applications in the food industry. To improve the hypolipidemic and hypoglycemic properties, coconut endosperm residue fiber (CERF) was modified by superfine-grinding and mix enzymatic hydrolysis alone, or combined with acetylation or hydroxypropylation. The effects of these modifications on the structure and functional properties were studied using scanning electron microscopy, Fourier-transformed infrared spectroscopy, and in vitro tests. After these modifications, the microstructure of CERF became more porous, and its soluble fiber content, surface area, water adsorption, and expansion capacities were all improved (p < 0.05). Moreover, superfine-grinding and mix enzymolysis combined with acetylation treated CERF showed the highest surface hydrophobicity (48.96) and cholesterol and cholate adsorption abilities (33.72 and 42.04 mg∙g^‒1). Superfine-grinding-, mix enzymolysis-, and hydroxypropylation-treated CERF exhibited the highest viscosity (17.84 cP), glucose adsorption capacity (29.61 µmol∙g^‒1), and glucose diffusion inhibition activity (73.96%), and water-expansion ability (8.60 mL∙g^‒1). Additionally, superfine-grinding and mix enzymatic hydrolyzed CERF had the highest α-amylase inhibiting activity (42.76%). Therefore, superfine-grinding and mix enzymolysis alone or combined with hydroxypropylation were better choices to improve hypoglycemic properties of CERF; meanwhile, superfine-grinding and mix enzymolysis combined with acetylation can effectively improve its hypolipidemic properties. PRACTICAL APPLICATION: This study offered three composite modification methods to improve the soluble fiber content and in vitro hypolipidemic and hypoglycemic properties of coconut endosperm residue fiber. These modification methods were practicable and low-cost. Moreover, it provides good choices to improve the functional properties and applications of other dietary fibers in the food industry.

The aim of this study is to develop roselle (Hibiscus sabdariffa L.) extracts with high amounts of phytochemicals and in vitro antioxidant and antibacterial effects using green extraction technique. Roselle extract prepared by ultrasonic extraction with 80% ethanol and 1% hydrochloric acid (RSUEH) promoted the highest yield and high total phenolic (5.21 ± 0.05 g% gallic acid equivalent of dried extract), total flavonoid (1.29 ± 0.06 g% quercetin equivalent of dried extract), and total anthocyanin contents (0.21 ± 0.00 and 0.44 ± 0.00 g% cyanidin 3-glucoside equivalent of dried extract determined by pH-differential method with standard calculation and pH-differential method with standard curve of cyanidin 3-glucoside, respectively). From the validated high-performance liquid chromatography analysis, delphinidin-3-sambubioside, delphinidin-3-glucoside, and cyanidin-3-glucoside were found to be the major anthocyanins in roselle extract. This extract exhibited moderate 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effect (EC₅₀ 289.61 ± 0.16 µg/mL) and strong inhibitory effects against Escherichia coli, Staphylococcus aureus, Staphylococcus intermedius, Proteus mirabilis, and Pseudomonas aeruginosa with the inhibitory concentration (IC₅₀) values in the range of 0.15 ± 0.05 to 4.64 ± 0.07 mg/mL and the minimum inhibitory concentration (MIC) values ranged from 1.66 ± 0.06 to 7.11 ± 1.05 mg/mL. From partial purification, fraction 28 (F28) contained higher amounts of all analyzed phytochemicals than roselle extracts and promoted stronger DPPH scavenging effects (EC₅₀ 54.88 ± 2.23 µg/mL). F28 showed antibacterial activity with IC₅₀ values against all tested bacteria in the range of 0.19 ± 0.07 to 4.69 ± 0.09 mg/mL, and the MIC values ranged from 2.46 ± 0.08 to 6.24 ± 0.09 mg/mL.

To investigate the effect of gamma irradiation on the volatile compounds of edible oils. Three types of oilseeds, including peanut, sesame, and flaxseed, were subjected to 8 kGy gamma irradiation, followed by cold pressing to extract their oils. The volatile compounds of the oils were isolated by simultaneous distillation extraction and analyzed by gas chromatography-mass spectrometry. A total of 91 volatile compounds were identified, which can be grouped into eight categories: hydrocarbons, aldehydes, ketones, alcohols, acids, esters, furans, and benzene derivatives. Irradiation treatment resulted in a significant increase in the levels of hydrocarbons, aldehydes, and ketones in all oil samples (p < 0.05), with the greatest increase observed in hydrocarbons (4-14 times). In contrast, changes in alcohols, acids, esters, furans, and benzene derivatives were related to oilseed type. The increased hydrocarbons mainly originated from the degradation of palmitic, stearic, oleic, and linoleic acids. The irradiation resistance of the three oilseeds varied considerably, in the order: flaxseed > sesame > peanut. Based on the odor activity value, 11 key aroma compounds were selected, and (E)-2-decenal (tallow, oily, and orange), 1-octanol (soapy and oily), and 1-nonanol (floral and soapy) were only detected in the irradiated samples. Principal component analysis revealed that the oil samples of the three oilseeds could be well classified based on their key aroma compounds, and that the irradiation treatment had no remarkable effect on their intrinsic aroma.

To investigate the effect of bound phenolics extracts (BPEs) of jujube peel on relieving cadmium (Cd)-induced toxicity and its mechanism, the behavioral deficits, lipid accumulation, and fatty acid synthesis-related gene expression in Caenorhabditis elegans in Cd exposure group and BPEs improvement groups were determined and compared. The results showed that BPEs significantly improved Cd-induced behavioral deficits in C. elegans, and no significant differences could be found in low-dose (12.5 µg/mL) and high-dose (100 µg/mL) BPEs improvement groups. The treatment of BPEs effectively improved intestinal injury and lipofuscin and lipid accumulation. Especially, oil red O staining intensity in C. elegans treated with BPEs at 50 µg/mL was reduced by 12.60%. BPEs significantly controlled the increase in content of C16:0, C16:1, C18:0, C18:1, and C18:2 induced by Cd by regulating the lipid accumulation in Escherichia coli OP50. Cd exposure induced lipid accumulation in C. elegans by upregulating oleic acid synthesis-related gene expression in E. coli OP50. Furthermore, BPEs treatment significantly downregulated the fatty acid synthesis-related gene expression in C. elegans and E. coli OP50. This research could reveal the mechanism of BPEs of jujube peel in relieving Cd-induced toxicity and provide a theoretical basis for the development of functional foods rich in polyphenols. PRACTICAL APPLICATION: Jujube peel, a by-product of jujube processing, is usually discarded due to its coarse texture. However, jujube peel has been proven to possess abundant polyphenols, polysaccharides, and cyclic adenosine phosphate. In addition, in our previous research, bound phenolics extracts (BPEs) of jujube peel were found to perform better in lowering lipid accumulation than that of free phenolics extracts. This study further investigate the effect of BPEs of jujube peel on relieving Cd-induced toxicity and its mechanism on the base of our previous research. It could realize the comprehensive utilization of by-products of jujube processing.