Food and Bioprocess Technology最新文献

The cambuci is a fruit that has been attracting interest due to its rich composition of phenolic compounds. However, the fruit’s peel is an understudied agro-industrial by-product. This study is aimed at assessing the effects of temperature and pH in an innovative system. This system integrates an in-line UV-VIS analysis detector into the process of extracting and hydrolyzing bioactive compounds from cambuci peel, enhancing process monitoring. The system operated with 2 g of cambuci peel in the reactor for 60 min, using a water flow rate of 2 mL min⁻¹, 15 MPa, temperatures ranging from 40 to 160 °C, and pH levels from 4 to 7. The results indicated that increasing the temperature led to a more favorable response in total phenolic compounds (TPC) and the antioxidant capacity of the samples. At the same time, the selected pH range had a minimal impact. Furthermore, the obtained material revealed the presence of citric acid, glucose, arabinose, and fructose, with fructose showing the highest concentration. The in-line coupling system proved to be highly effective in real-time monitoring and determining the completion of the extraction or hydrolysis process, as it allowed for the observation of decreasing concentrations of the compounds of interest. Thus, this study contributes to the understanding and optimization of the extraction of bioactive compounds from cambuci peel, providing valuable insights for future applications in the food and natural products industry.

This research aimed to develop a 3D-printed pasta formula that, when cooked in various-flavored waters, turns its color into appealing colors that can be used as a cooking indicator. For this aim, a new pasta formula composed of wheat flour (WF), olive oil (EVOO), and red cabbage juice (RCJ) (containing the smart material anthocyanin) was used as print inks. Rheological properties, textural profile analysis, printability and printing accuracy of various pasta dough formulations were first investigated. Subsequently, the color changing, cooking quality, flavor profile (by E-nose) and consumer acceptability of fresh and freeze-dried (FD) 3D-printed pasta cooked in various-flavored waters were evaluated. Results revealed that adding EVOO enhanced the printability and smoothness of the pasta dough. Moreover, the colors of both 3D fresh and FD pasta progressively turned from light blue (before cooking) to uniform red, red/orange, and green after cooking in lemon, orange, and chencun/alkaline waters, respectively. Additionally, cooked fresh and FD pasta showed acceptable and good cooking quality. Furthermore, significant flavor differences among cooked 3D pasta specimens were detected. This study paves the way for developing new 4D pasta products with appealing colors that can be used as a cooking indicator and enhance consumer interaction with pasta during cooking.

Time and temperature are the crucial factors affecting the quality of perishable products. The device capable of recording temperature fluctuation and maintaining time has huge practical potential. In this research, a novel thermal history indicator (THI) was proposed based on covalent organic frameworks (COFs) with the irreversible color change performance. The color change and absorbance of the THI were investigated over a broad monitoring temperature range (− 22 ~ 55 ℃) and were closely correlated with its thermal accumulation over time and temperature. The activation energy (E_a) of the THI was calculated to be 55.31 kJ mol⁻¹, which can be used to monitor the perishable products with deterioration reaction E_a ranging from 30.31 to 80.31 kJ mol⁻¹. In addition, the THI also demonstrated the significant response to the environmental temperature fluctuations. Furthermore, the potential applications were evaluated by recording the changes of the THI gel and the total viable count (TVC) of food under the same conditions. The results indicated that the digital images of the colorimetric THI gel were correlated with TVC of food at 4 ℃ and 25 ℃, respectively. These results support that the proposed THI is potential for real-time, accurate, non-destructive, visually, and quantitatively monitoring food freshness during food supply chain distribution.

Graphical Abstract

Self-assembly and molecular spectroscopy are widely used in protein research. However, studies underreported the interaction of rice glutelin (RG) and egg white protein (EWP) under pH-cycle treatments, which had differences between initial and final environment. Herein, the possible interaction mechanism of RG-EWP self-assembly behavior was demonstrated by spectroscopy or other characterization methods under different conditions and proportions. Fourier transform infrared, circular dichroism, intrinsic fluorescence, and UV absorption spectroscopic methods showed changes in the secondary and tertiary structures of RG or RG-EWP. Results also revealed the degree of protein folding and exposure status of aromatic amino acid residues. The nonignorable surface hydrophobic and electrostatic interactions were observed by ζ-potentials and surface hydrophobicity. The electrophoretic analysis showed increased 48 kDa subunits. The high solubility (over 92%) of RG-EWP was discovered as potential functionality at total ratio of 90% and 50% RG. This study improved the asymmetric pH-cycle theoretical mechanism and widened RG-EWP application.

Graphical Abstract

Interventions in the upstream production and further processing of recombinant food proteins affect its properties when used for food application. Often the efficiency of particular interventions is evaluated based on molecular purity and yield rather than final functional properties. Yet, the formulation of foods, including the amount of protein required, can be affected when the functional properties have changed. In this explorative study, we exemplify how far we can extend the functionality range of the major whey protein β-lactoglobulin (BLG), in terms of foaming and (heat-set) gelling, through various interventions. Slight changes in the amino acid sequence of BLG affected its functional properties significantly. Foams were up to ten times more stable, when selecting different natural isoforms of BLG (isoform A instead of B) or when inducing targeted cysteine mutations. The isoform B yielded stronger thermally induced gels (+ 40%) compared to isoform A. During downstream processing of recombinantly secreted BLG, limited purification of up to ~ 67 wt% enabled reasonable foaming properties and superior gelation, while a lower purity of ~ 22 wt% resulted in poor performance in both cases. Post-processing allowed conversion of native whey protein into soluble amyloid-like aggregates. These aggregates resulted in better foam stability (i.e., approximately four times longer than non-aggregated protein), but did not improve gelation. The presented study demonstrates that one should consider not only protein yield and purity, but also functional properties when developing recombinant proteins for food application. In turn, these functional properties are a result of the complete upstream and downstream chain.

Staphylococcus aureus is a common Gram-positive pathogen that causes food poisoning and foodborne illnesses. In this study, a peptide-designated NGJ1D (GAPNDLTARFIAKK) was found among 8 peptides in the fermentation broth of Lacticaseibacillus paracasei. NGJ1D had a minimum inhibitory concentration (MIC) of 62.5 μg/mL against Staphylococcus aureus and could kill the bacteria within 3 h. In a mimicked bacterial cell membrane environment, NGJ1D could change its secondary structure from a random coil to an α-helix to increase its membrane permeability and subsequent interaction with bacteria genomic DNA. Further analysis using SDS–polyacrylamide gel electrophoresis, ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS), and molecular docking revealed that NGJ1D affects the DNA-binding protein HU of S. aureus to interfere with DNA synthesis. These results indicate that novel peptides with antimicrobial potential, such as NGJ1D, could be identified in fermentation broths and can be used for application in food preservation and the prevention and treatment of infections caused by S. aureus.

A natural nano-edible coating based on fish gelatin-rosemary essential oil was developed for the preservation of blunt snout bream (Megalobrama amblycephala) fillets. The results showed that the coating treatment effectively maintained the texture stability of the fish fillets, including appearance and water-holding capacity, significantly delayed lipid and protein oxidation, and inhibited microbial growth. On day 10, compared to the CK group, the TVB-N and TVC of the CT decreased by 41.46% and 31.36%, respectively. Proteomics was used to reveal the biochemical mechanisms affecting fish quality characteristics. Bioinformatics analysis of differential abundant proteins (DAPs) showed that the effects of the coating were related to the cellular process, skeleton structure, and enzymatic activity. Meanwhile, 65 DAPs which related to quality changes were further screened out, and most DAPs showed upregulation in coated fish fillets compared to the control, including myosin heavy chain, myosin-7, T-complex protein 1, isocitrate dehydrogenase (NADP (+)), 40S ribosomal protein, and HSPs, while Prdx-6 showed downregulation. It is believed that the coating delayed and prevented the generation of microbial degradation products and reduced the damage to the protein structure by suppressing microbial growth and protease activity, thereby stabilizing texture properties of refrigerated fish fillets. The shelf life of fillets during storage at 4 °C was significantly extended by at least 30%. The study provides an innovative method for the fish preservation and a theoretical basis for the protective effect of the coating on protein structures at the molecular level.

Lanthanides were tested (Ce³⁺, Er³⁺, and Yb³⁺) as catalysts to produce lactic acid (LA) from the monosaccharides present in corn stover (glucose, xylose, and arabinose) resulting in ytterbium being the most active. A MW-heated system led to similar LA yield as a conventionally heated pressurized system. The maximum value of LA yield was 40% at 240 °C after 20 min of isothermal treatment regardless the starting monosaccharides, which allowed to propose a similar LA production route based on the products profile determined along time for the three monosaccharides. Temperature and time determined the product profile, observing furfural degradation at severity factors higher than 3.5, while values higher than 5.5 were needed to observe LA degradation. By increasing temperature, catalyst solubility decreased, increasing its presence in the solid residue after treatment. Xylan conversion to LA was similar as for xylose, but lower yield was obtained from microcrystalline cellulose. Corn stover presented more amorphous regions leading to higher hydrolysis yields of its cellulose fraction.

Controlled release of curcumin by a pH-sensitive carrier provides long-term preservation, which extends the shelf lives of fish. FTIR, XRD, ¹H NMR, zeta potential, swelling ratio, and TG analyses indicated that a pH-sensitive starch-based carrier with a narrow pH-sensitivity range (pH 6–7) was fabricated from the carboxymethyl starch grafted with methacrylic acid and then cross-linked with β-cyclodextrin to achieve dual functionality. FTIR, XRD, and fluorescence spectroscopy revealed that the mechanism by which curcumin was encapsulated in the starch-based carriers involved hydrophobic interactions and intermolecular hydrogen bonding. The encapsulated curcumin showed improved stability, higher antioxidant activity, antibacterial activity, and biocompatibility. The pH, TVB-N, TVC, and drip loss tests confirmed that the use of the carrier-curcumin complex at a concentration of 10 mg/mL for the preservation of yellow catfish extended the shelf life for 2–4 days during cold storage and improved the storage quality of the resulting fillets. This work provides a dual functionality strategy for constructing a pH-sensitive starch-based carrier to deliver curcumin and offers a promising choice for fish preservation.

Graphical Abstract

Selenylation modification is an effective way to improve the nutritional and health effects of tea polysaccharide, but the effects of different selenylation methods on the structure and efficacy of polysaccharides remain unclear. In this study, a series of chemically selenized tea polysaccharides (CSe-TPS, selenium content of 129.98 ~ 1454.99 µg/g) were prepared by Na₂SeO₃-HNO₃ method, which were promoted by heating (HCSe-TPS), ultrasound (UCSe-TPS), and pulse electric field (PCSe-TPS) treatments, respectively. These different CSe-TPSs were systematically compared with ordinary tea polysaccharides (Ord-TPS) and natural selenium-enriched tea polysaccharides (NSe-TPS) in aspect of molecular structure and biological functions. The results of molecular structure and apparent morphology showed that the particle size (p < 0.05) and the thermal stability of Ord-TPS were reduced after selenylation modification, while the absolute potential of polysaccharide was increased (p < 0.05), coupled with altered monosaccharide composition and changed apparent morphology. However, the main functional groups and the secondary structure of Ord-TPS did not change. The antioxidant activities of tea polysaccharides after selenylation were improved as well as their inhibitory effects on carbohydrate digestive enzymes (p < 0.05). The total antioxidant capacity of PCSe-TPS (selenium content of 240.66 ± 1.43µmol/g) was enhanced by 85.41% compared with Ord-TPS (selenium content of 129.80 ± 3.42 µmol/g), while its IC₅₀ values on inhibition of α-amylase (2.91 ± 0.18 mg/mL) and α-glucosidase (0.18 ± 0.01 mg/mL) were significantly lower than other tea polysaccharides (p < 0.05), which suggested best antioxidant and hypoglycemic activity. Moreover, tea polysaccharides with higher selenium content and smaller particle size showed better antioxidant and hypoglycemic activities. This research will provide new strategies for the application of tea polysaccharides.