Food and Bioproducts Processing最新文献

Electric field technology has been highlighted as a promising strategy in the permeabilization of cell membranes and the corresponding bioactive release. In this work, aqueous and ethanolic suspensions of Pavlova gyrans were subjected to moderate electric fields (MEF) to promote rapid heating due to Ohmic Heating (OH) effect. Two approaches were tested: i) OH assisted extraction in a temperature range between 25 ºC and 85 ºC, and ii) OH pretreatment at 25 ºC and 55 ºC followed by solvent extraction. OH treatment at 55 ºC (performed in less than 10 s) in aqueous suspensions promoted a marked increase in the release of organic matter (2.1-fold), chlorophyll a (41.1-fold) and total carotenoids (56.6-fold) when compared to the freeze-thaw cycles (FTC ≈ 3 hours). OH-pretreated biomass subjected to a two-step passive extraction improved the release of proteins and chlorophylls over incubation (p < 0.05) when compared to untreated biomass. This procedure increased 2.2-, 3.9- and 31.9-fold the content of organic matter, protein and chlorophyll a, respectively, in comparison to the FTC procedure. This work presented the OH effect as a promising strategy for enhanced disruption and release of intracellular microalgae compounds.

This study compared beef jerky produced by conventional cooking and UV-A light dehydration. The analyses included the isopiestic method, colorimetric analysis, electron microscopy, infrared spectroscopy, and microbial inactivation studies. The primary criterion was a water activity (a_w) value of < 0.85 to optimize UV-A dehydration time, taking 4.5 h to achieve this level. UV-A light dehydration resulted in significantly less browning compared to conventional cooking, yielding a duller, less red product (P < 0.05). Electron microscopy showed that UV-A light dehydration maintained a more uniform microstructure, while conventional cooking caused more structural deffects. Microbial inactivation studies demonstrated the antimicrobial effect of UV-A light by reducing accessible water (a_w < 0.85). The hygroscopicity of UV-A light dehydrated jerky was similar to conventionally cooked jerky. Overall, UV-A light-dehydrated beef jerky had similar characteristics to conventionally cooked jerky but with notable differences that could appeal to specific consumer preferences.

Effects of clarification with “tannase,” “tannase+lactonase,” “papain,” “aspartic protease” and “tannase+lactonase+papain” on defects (turbidity, sediment and color loss) and important constituents (phenolics, anthocyanins, proteins and amino acids) of pomegranate juice (PJ) were investigated. Lactonase [human-derived (H-PON-1 and H-PON-2) and rabbit-derived (R-PON-1, R-PON-2 and R-PON-3)] was used during juice clarification for the first time. Phenolics and amino acids were quantified by HPLC-DAD-MS and HPLC. After clarifications with “tannase (1 g/L)+R-PON-1 (0.33 mg/L)” and “tannase (1 g/L)+R-PON-1 (0.33 mg/L)+papain (10 mg/L)” at 30℃ for 90 min, sediment was completely eliminated during storage at 20℃ for a month. Among these treatments, “tannase+R-PON-1” provided the lowest turbidity formation rate. The most effective parameter to prevent sediment was the ratio of “prolamin to trigalloyl-HHDP-glucose-isomer-2” that should be ≥205.4 (r=–1.000). Moreover, “tannase+R-PON-1” caused 4.3 times lower turbidity than control group after storage. To retain low turbidity (≤10 NTU) during storage, galloyl-glucose-isomer and HHDP-galloyl-hexoside-3 should completely be removed from PJ and, punigluconin and trigalloyl-HHDP-glucose-isomer-2 contents should be ≤0.19 and ≤0.04 mg/L, respectively. Furthermore, “tannase+R-PON-1” provided a significant contribution to anthocyanin copigmentation. The most effective copigments in PJ were HHDP-galloyl-glucuronide, punigluconin, punicalagin-2, punicalagin-3, aspartic acid, glutamic acid and alanine. “Tannase+R-PON-1” is recommended to produce a high-quality PJ.

Complex cohesions were formed through electrostatic interactions between gelatin (GE) and gum arabic, sodium carboxymethyl cellulose, pectin, and sodium alginate (SA). Of them, GE and SA served as an ideal wall material for encapsulating oregano essential oil (OEO). Applying the composite coalescence method, we here generated unique encapsulated OEO microcapsules (EOMs) by using GE–SA as the microcapsule wall material and OEO as the core material. At a concentration of 1 % (w/v), a core-to-wall ratio of 1:2, a recoalescence reaction temperature of 45 °C, and an emulsifier concentration of 5 % (w/w), EOMs exhibited excellent performance. Under the optimal conditions, the prepared EOMs (average particle size: 78.389 μm) had a homogeneous and complete spherical structure. Freeze-dried EOMs had a high encapsulation efficiency (71.20 %) and payload (56.08 %). Fourier transform infrared spectroscopy unveiled the presence of electrostatic interactions between GE and SA. The OEO in the EOMs had higher thermal stability and more stable antioxidant properties than the free OEO. Furthermore, in aqueous, acidic, oily, and alcoholic environments, EOMs exhibited some degree of slow-release ability. Additionally, EOMs exhibited strong antibacterial properties, with effective inhibition of Escherichia coli (E. coil), Staphylococcus aureus (S. aureus), and Curvularia lunata (C. lunata). Among them, the strongest inhibitory effect was on C. lunata. In summary, microcapsules prepared using GE–SA as a wall material had effectively improved OEO degradation-protecting, which enhanced the stability of OEO and controlled its antioxidant properties. Meanwhile, the microcapsules exhibited excellent antibacterial properties. This system exerted considerable potential in protecting the stability of essential oils and realizing slow release.

Baijiu is a unique alcoholic beverage in China, prepared through a traditional solid-state fermentation process. Daqu, recognized as the earliest form of crude enzyme preparation, plays a crucial role in determining the quality of Baijiu. Due to the enzymatic process derived from natural fermentation, the differences between regions were expected to occur. To compare regional-difference in microbial diversity and the functional profile of Daqu, metagenomic sequencing, physicochemical analysis, and electronic sensory evaluation were utilized. The results showed that bacteria and fungi were the main microbes in low-temperature Daqu (LTD), and their ratio of abundance was approximately 9:1. Streptomyces (20.27 %) and Bacillus licheniformis (15.28 %) emerged as the most dominant microbes in LTD at the genus and species levels, respectively. The overall microbial communities and functional profiles of Daqu between the two regions exhibited significant differences (P < 0.05). Bacillus licheniformis was significantly enriched in LTD from Taiyuan (P < 0.05) and mainly contributed to the saccharifying power, fermenting power, esterifying power, and liquefying power of LTD, demonstrating its important role in maintaining LTD quality. LTD from Taiyuan had a significantly higher fermenting power, esterifying power, and liquefying power than LTD from Suizhou (P < 0.05). In addition, a higher abundance of genes responsible for lactate production was detected in LTD from Suizhou, whereas genes associated with acetate production were enriched in LTD from Taiyuan. Collectively, these findings indicated that lactic acid bacteria may play a more important role in LTD from Suizhou, whereas acetate-producing bacteria may have a greater contribution to LTD from Taiyuan. This study provides a reference for microbial regulation during the production process of Daqu, and control of quality and traceability of the origin of Daqu.

Expanding the utilization of bamboo shoots is extremely meaningful in China because of the high output every year. In this study, the bamboo shoot powder was used as a substrate to produce water-soluble dietary fiber (WSDF) by fermentation with a screened fungi strain Trichoderma dorotheae MLG23, and the prepared WSDF was utilized in the production of biscuits. The bamboo shoots and their residues, WSDF, and biscuits were analyzed on Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and texture analyzer. The results showed that the fungi exhibited a strong ability to express extracellular cellulase. The enzymatic activities of filter paper activity (FPA), cellobiohydrolase (CBH), and ꞵ-glucosidase (BG) secreted by the strain showed the highest at 50 °C, reaching 0.13, 0.19, and 1.20 U/mL, respectively, and the highest enzymatic activity of endoglucanase (EG) with 0.37 U/mL was obtained at 60 °C. The highest WSDF yield of 45.97 wt% was obtained under the fermentation conditions of bamboo shoot loading 30 g/L, strain inoculum 10¹⁰ CFU/L, and fermentation time 4 d at 30 °C. The cellulose and hemicellulose in bamboo shoots were partially utilized by the fungi to produce WSDF. The main metal elements in WSDF were Mg, K, Ca, and Zn. The hardness, cohesion, chewiness, resilience, and adhesion of the biscuits showed a gradual decrease with the increase of WSDF addition in the range from 0 to 10 g per 100 g of low gluten flour. The incorporation of WSDF disrupted the network structure of the gluten, leading to the reduction of some textural properties and the change of microstructure. These results showed a potential utilization of bamboo shoot in production of WSDF and functional biscuits.

The use of microdevices in extraction processes in aqueous two-phase systems (ATPS) has been studied for years in the literature. However, the effects of flow patterns still need to be adequately explored, especially for real samples. In this sense, the present study investigated the performance of microdevices in the recovery and partial purification of invertases with varying flow patterns. The invertases from Saccharomyces cerevisiae and the polyethylene glycol 1500/magnesium sulfate system were used in the experiments. Beyond the flow pattern, the study sought to maximize recovery and purification factor (PF) values by varying other operating conditions, including residence time, volumetric ratio, and channel diameter. It was observed that the short slug and long slug patterns showed better separation performance than the parallel pattern regardless of residence time and volumetric ratio. Increasing the residence time from 15 to 35 min increased the top recovery and PF values by two times, indicating that S. cerevisiae invertase partition is slow to the top phase. The maximum values of recovery (57.01 % ± 2.67 %) and PF (4.16 ± 0.06) were reached in the condition with long slug pattern, 35 min of operation, volumetric ratio of 2:1, and a channel diameter of 0.51 mm. The present study provides valuable information for integrating microdevices in a protocol for purifying invertase from S. cerevisiae and other proteins in real systems.

In this study, natural deep eutectic solvents (NADES), comprising choline chloride (ChCl) as hydrogen bond acceptor (HBA) with hydrogen bond donor (HBD) including glucose (Glu), fructose (Fru), xylose (Xyl), xylitol (Xyli), and glycerol (Gly), were formulated and characterized for simultaneous extraction of phenolic compounds (polar) and carotenoids (non-polar) from fresh oil palm leaves (OPL). pH, density, polarity, Fourier Transform Infrared Spectroscopy (FT-IR) and rheological analyses were conducted, with relation to the extraction efficiency achieved via homogenizer-assisted heating and stirring extraction approach. Among the NADES formulations tested, ChCl:Xyl (1:1) displayed the highest total phenolic content (TPC) at 20.23825 mg/g OPL, due to its optimal polarity at 49.4654 kcal ${\mathrm{mol}}^{-1}$ and a viscosity of 23288 mPa.s. The highest total carotenoid content (TCC) was observed in ChCl:Xyli (1:1) at 325.94 µg/g OPL, with a lower polarity at 50.0280 kcal ${\mathrm{mol}}^{-1}$. Despite having similar viscosity and polarity, ChCl:Fru (1:2) with a pH of 5.82 outperformed ChCl:Glu (1:1) with a pH of 6.72 due to enhanced phenolic compound solubility and stability. This study shed light on the potential of NADES, particularly in overcoming the challenge of high moisture content in OPL and other fresh biomasses, which often acted as a barrier during phytonutrients extraction.

A mutant of cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE H356N) was studied for obtaining higher yield of oligosaccharides than by lactose transgalactosylation with Aspergillus oryzae β-galactosidase (AO-βG). Firstly, heterologous production of CsCE H356N was optimized in Luria-Bertani broth and minimal medium. Then, CsCE H356N and AO-βG were used for the synthesis of oligosaccharides varying the sequence of reactions, temperature, and enzyme load. Reactions sequence did not affect the global yield (∼51 %) but modified the product composition. At the best conditions tested, the global yield increased twice with respect to GOS synthesis with AO-βG (25.6 %). When GOS synthesis was followed by the isomerization/epimerization of unreacted lactose, the final product had a higher content of lactulose and GOS than when the reactions sequence was inverted. In the former case lactulose-derived oligosaccharides (fGOS) and fructose were absent, while in the latter the final product mainly contained fGOS, small amounts of GOS, lactulose and fructose. Epilactose content was similar in both sequences.

A large-capacity radio frequency (RF) rotation heating system was employed in this study to heat dried black fungus, and hot air was used for assistance treatment. The effects of electrode gap, rotation rate and hot air on the uniformity of RF heating of dried black fungus were explored. The optimal heating process parameters were obtained, and the sterilization effect was validated. The results showed that the rotation system could significantly enhance the RF heating uniformity of black fungus (P > 0.05). The optimal heating process for heating a large-capacity (480 g) black fungus was to utilize RF heating assisted by 70 °C hot air with an electrode gap of 175 mm and a rotation rate of 60 rpm, followed by 30 min of heat preservation at 70 °C hot air with a rotation rate of 40 rpm. After the entire sterilization treatment, the heating uniformity index λ of black fungus was reduced to 0.027 ± 0.004, the total plate count decreased by 3 log CFU/g, and the moisture content dropped to below 13 %. The ideal RF heating uniformity and sterilization effect of black fungus were obtained in this study through the simultaneous use of hot air and rotation, providing a theoretical foundation for the application of RF technology in the processing of black fungus.