L-Arabinose isomerase (L-AI) catalyzes the isomerization of galactose to tagatose, a functional rare sugar with wide applications in the food and pharmaceutical industries. To improve its stability, this study developed a magnetic chitosan/calcium pyrophosphate hybrid nanoflower platform (CTM) for the immobilization of Lactobacillus fermentum L-AI (LfAI) through the functionalization of magnetic nanoparticles and a biomineralization strategy. The obtained CTM@LfAI exhibited an encapsulation yield and activity recovery of 81.19% and 59.56%, respectively, exhibiting a good immobilization efficiency. Compared with the free LfAI, CTM@LfAI exhibited an enhanced thermal stability, with a Tm value of 81.7 °C, significantly higher than 73 °C for free LfAI. Moreover, CTM@LfAI could be easily recovered by a magnet and 73.72% of its initial activity was retained after eight reuse cycles, which was much better than the non-magnetic immobilized enzyme CT@LfAI, demonstrating excellent operational stability. Moreover, compared to free LfAI, CTM@LfAI achieved an equivalent yield of 45.86% in galactose-to-tagatose bioconversion. Dual-enzyme cascade systems combining β-galactosidase from Aspergillus oryzae (Aoβ-Gal) with LfAI were constructed to explore their ability to valorize lactose for tagatose production. The final tagatose yields for free Aoβ-Gal + free LfAI system and free Aoβ-Gal + CTM@LfAI system were 25.82% and 22.75%, respectively. In summary, the magnetic hybrid nanoflower developed in this study provides a promising platform for the efficient, recyclable, and stable immobilization of L-AI, indicating its potential for further development in tagatose production.

Tagatose, a functional ketose produced by galactose isomerization, faces production challenges due to reaction equilibrium limitations and the difficulty of separating similar sugars. This study developed an integrated strategy to overcome these hurdles by combining enzymatic catalysis with selective adsorption. Mesophilic and thermophilic l-arabinose isomerases (l-AIs), namely BtAI from Bacillus thermoglucosidasius and LfAI from Lactobacillus fermentum, were engineered to catalyze the conversion of galactose into tagatose. After systematic optimization, the BtAI-catalyzed galactose isomerization produced 15.05 g/L tagatose with a yield of 47.68 %, whereas the LfAI-catalyzed reaction produced 17.87 g/L tagatose with a yield of 53.05 %. In addition, dual-enzyme cascade systems combining β-galactosidase (β-Gal) with l-AIs were constructed to explore their ability to valorize lactose for tagatose production. The BtAI-based dual-enzyme cascade system produced 23.93 g/L tagatose with a yield of 23.26 % from lactose, whereas the LfAI-based system resulted in 21.89 g/L tagatose with a yield of 19.72 %. To address purification and equilibrium constraints, a low-pKa boronate affinity adsorbent (PBA@AR) with high tagatose selectivity was synthesized. Implementing a PBA@AR-mediated adsorption-assisted isomerization strategy drove the reaction equilibrium forward, increasing the final tagatose yield to 67.07 % while simultaneously achieving a product purity exceeding 95 %. This work provides an efficient approach for enhancing both the yield and purity in enzymatic ketose production.

In this study, a boronate affinity material (FA-5) with a low pKa value was prepared to facilitate lactulose production. At physiological pH, 58.23 % of the B atoms in FA-5 existed in an sp3 hybridization state, and FA-5 demonstrated excellent adsorption capacity (94.78 mg/g) and selectivity (91.82 %) for lactulose from a 1:1 lactulose-lactose solution. Additionally, FA-5 demonstrated an exceptional capability for separating lactulose. The purity of lactulose increased by up to 6.82-fold in lactulose-lactose solutions with varying concentration ratios. A cascade system was formed by an immobilized enzyme-packed column with an FA-5-packed column to enhance lactulose production and purification. By adopting the adsorption-assisted isomerization strategy, the lactulose yield was improved from 52.50 % to 71.14 % with lactulose purity reaching 83.57 %. Moreover, the cascade system demonstrated excellent catalytic stability (86.28 %) and adsorption stability (93.68 %) over six consecutive cycles. The results highlight the potential of the cascade system for enzymatic production of lactulose.

Cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) is an efficient enzyme for lactulose production. However, the use of free enzymes, restricted product yields, and challenges in lactulose separation hinder its industrial applications. In this work, CsCE-inorganic hybrid nanocomposites were synthesized by combining chitosan/tripolyphosphate (CS/TPP) ionotropic gelation with Ca2+-mediated bio-mimetic mineralization. Under optimized conditions (0.4 mg/mL of CsCE, 2 mg/mL of CS, and 125 mg/mL of TPP), the as-prepared CS/TPP-Ca@CsCE possessed a porous hierarchical flower-like spherical structure and showed effective encapsulation yield and activity recovery of similar to 95 % and 97.20 %, respectively. Compared to free CsCE, the CS/TPP-Ca@CsCE exhibited improved catalytic activity and stability toward pH (pH 5-9) and temperature changes (60-80 degrees C). Kinetic parameters of CS/TPP-Ca@CsCE were greatly improved with increased substrate affinity (Km-app 68.74 mM vs. 90.19 mM) and enhanced catalytic efficiency (eta(app) = 0.032 s(-1)mM(-1) vs. 0.028 s(-1)mM(-1)). The applied CS/TPP-Ca@CsCE did not change the lactose-to-lactulose isomerization equilibrium, and the final ratio of lactose: lactulose: epilactose was stabilized at similar to 30 %: 12 %: 58 %. To further enhance the lactose-to-lactulose conversion, a low-pK(a) boronate-affinity adsorbent (AR@PBA) was synthesized and incorporated into the CS/TPP-Ca@CsCE-catalyzed isomerization system. Under physiological pH, the selective adsorption of lactulose by AR@PBA enabled a significantly enhanced lactulose yield from 59.40 % to 75.65 %. More importantly, the adsorbed lactulose could be efficiently recovered with purity reaching up to 95.51 %. These results suggested that the boronate-affinity adsorbent-mediated enzymatic isomerization of lactose is an effective approach for lactulose production.

Lactulose, a nondigestible disaccharide, is widely recognized for its significant health-promoting effects. The drawbacks of traditional chemical catalysis, e.g., high environmental pollution and complex separation processes, hinder its sustainable production. In this study, an in vivo cascade system, integrating a cellobiose 2-epimerase (CE) and a mannose isomerase from Marinomonas mediterranea (MmMI), was proposed to produce lactulose from lactose-rich dairy waste. The cascaded system improved the conversion of lactulose up to 90% by eliminating the accumulation of the byproduct epilactose. Moreover, loop-B was revealed to be a crucial structural region for isomerization; upon this new discovery, semirational modification of MmMI by reshaping loop-B resulted in a 17.5% increase in lactulose production. Furthermore, this in vivo cascade cell factory was optimized via ribosome binding site (RBS) engineering. Upon high-density fermentation, a total of 59.3 g/L lactulose was obtained using whey powder as the raw material. This efficient in vivo multienzyme cascade system demonstrates substantial potential for the large-scale production of lactulose.

The construction of immobilized β-galactosidase with structural robustness and enhanced transglycosylation activity represents a promising approach to elevate the functional properties of dairy products. In this study, the β-galactosidase from Kluyveromyces lactis was immobilized onto Duolite A568, a macroporous anion-exchange resin, through electrostatic adsorption followed by glutaraldehyde crosslinking. The immobilization conditions were optimized, and the retention of the maximum enzymatic activity was obtained after incubation at pH 4.5, with an enzyme concentration of 2.0 mg/mL for 60 min, resulting in a high enzyme loading capacity of ∼27 mg/g resin. Post-crosslinking with 0.1 % glutaraldehyde remarkably enhanced the relative activity of the immobilized enzyme to 144 % compared to the non-crosslinked adsorbed enzyme. Notably, a novel sugar-assisted immobilization strategy was introduced by incorporating sugars at specific immobilization stages. Comparatively, the lactose-assisted crosslinking approach exhibited exceptional performance, yielding immobilized β-galactosidase (labelled as ACP-β-galactosidase) with a relative activity of 226 %. ACP-β-galactosidase maintained high activity over a broad pH range (4.0-10.0) and retained over 80 % of its initial activity after ten catalytic cycles, indicating high operational stability. Further investigation on the transglycosylation activity of the ACP-β-galactosidase in terms of the yield of lactulose was conducted in the presence of fructose. The ACP-β-galactosidase achieved a lactulose yield of 60.45 g/L (conversion ratio: 24.92 %), markedly higher than that of the free enzyme (39.55 g/L, 16.23 %). This study not only provides a robust lactose-assisted immobilization strategy for constructing high-performance β-galactosidase biocatalysts but also presents a new trial for altering the lactulose biosynthesis through immobilization-induced modulation of β-galactosidase functionality.

Caldicellulosiruptor saccharolyticus cellobiose 2-epimerase (CsCE) is recognized as a highly efficient lactulose-producing enzyme. However, the intrinsic drawbacks of free enzymes significantly hinder their industrial applications. In this study, the reusable paramagnetic nickel ferrite nanoparticles (NiFe2O4 NPs) were synthesized via a facile one-pot hydrothermal method and subsequently employed for selective immobilization of histidine-tagged (His-tagged) CsCE through Ni2+-mediated affinity coordination. The NiFe2O4 NPs possessed a mesoporous structure with an average pore diameter of 14.61 nm and a large specific surface area (136.51 m2/g), which facilitates a high CsCE loading capacity of >100 mg/g. Upon immobilization, the obtained NiFe2O4@CsCE exhibited efficient immobilization efficiency of 82.22 % with activity recovery of 49.28 %. Notably, Ni2+-directed affinity immobilization enabled >85 % selectivity for His-tagged CsCE. Moreover, the resulting NiFe2O4@CsCE with strong magnetic responsiveness (Ms 34.59 emu/g) allows facile and efficient magnetic separation. It also exhibited a broad thermal stability and maintained more than 84 % of its initial activity after eight catalytic reuses, demonstrating an excellent reusability. Compared to free CsCE, NiFe2O4@CsCE displayed an equivalent catalytic ability in lactulose biosynthesis with an equilibrium yield of lactulose (58.46 % ∼ 59.94 %). Interestingly, NiFe2O4@CsCE could be easily regenerated through imidazole elution. After five immobilization-reaction-regeneration cycles, NiFe2O4@CsCE retained over 76 % of its initial activity and maintained a CsCE loading capacity of approximately 50 mg/g. These findings demonstrate that the applied Ni2+-mediated affinity immobilization strategy enables integrated purification and immobilization of target CsCE, coupling facile magnetic recovery with robust enzymatic performance, highlighting its strong potential for scalable lactulose biomanufacturing.

Boronate affinity materials (BAMs) are effective in enhancing aldose-ketose isomerization, though their performance varies significantly between monosaccharides and disaccharides. In this study, a spherical phenylboronic acid-functionalized adsorbent (PFA) featuring controlled particle size, high adsorption efficiency, and compatibility with fixed-bed systems was prepared via suspension polymerization. The mechanism by which sugar-binding affinity differences regulate PFA-mediated aldose-ketose isomerization efficiency was investigated. PFA exhibits high efficiency in separating tagatose from a typical aldose-ketose mixture (tagatose and galactose). Tagatose purity increased from 50 % to 84.14 % through selective adsorption and was further enhanced to 96.92 % via a stepwise desorption strategy. PFA achieved equilibrium absorption within 10 min, enabling rapid capture of the ketose product in the isomerization system. The binding affinities of PFA toward monosaccharides and disaccharides were evaluated using isothermal titration calorimetry (ITC). Results revealed greater binding affinity differences for disaccharides [Delta Ka (lactose-lactulose): 2.055 x 103 M- 1] compared to those for monosaccharides [Delta Ka (galactose-tagatose): 1.534 x 103 M- 1]. By adopting different adsorption strategies, PFA was applied to monosaccharide and disaccharide isomerization reactions. Compared to batch adsorption, the one-pot adsorption-assisted strategy more effectively improved tagatose yield and purity, reaching 54.29 % and 85.62 %, respectively. Moreover, PFA exhibited superior performance in disaccharide isomerization, with lactulose yield reaching 67.37 % and purity exceeding 98 % from lactose isomerization. The results demonstrated that greater aldose-ketose affinity differences in disaccharide systems more effectively promoted isomerization. Combined with the analysis of boron hybridization states during isomerization, these findings reveal a pH-driven mechanism in PFA-mediated adsorption-assisted isomerization regulated by distinct aldose/ketose binding affinities.

D-tagatose, a low-calorie sweetener with well-documented health benefits, has gained increasing attention. Traditional chromatographic methods for quantifying D-tagatose are costly, complex, and dependent on column separation efficiency and sample pretreatment. Developing reliable alternative detection methods is crucial to promote D-tagatose production and application. This study developed and optimized a rapid and cost-effective spectrophotometric method (SM) for quantifying D-tagatose based on ketose transformation under acidic conditions and visualization with tryptophan-L-cysteine. Under optimal conditions (62

Lactiplantibacillus plantarum (LP) is a well-known probiotic strain that has a beneficial effect in preventing ulcerative colitis. However, delivering a sufficient number of viable LP to the colon still face challenges due to its vulnerability to the highly complex intestinal flora ecosystem. Herein, we present a centrifuge-driven micronozzle system designed for double-layered core-shell alginate microcapsules (DAM), which can serve as an effective carrier for dual delivery of resistant starch nanoparticles (RSNP, prebiotic) and LP (probiotics) for the treatment of colitis. This system enables precise loading of LP and RSNP within the core and shell regions of DAM, respectively. The resulting LP/RS@DAM exhibited a high encapsulation efficiency of LP (108 CFU per bead), in which the dense distribution of RSNP in the shell effectively protected LP against acidic conditions (pH 2) and maintained the cell viability up to 52 % even after long-term storage for 30 days. Furthermore, LP/RS@DAM effectively enhances the production of short-chain fatty acids, leading to a reduction in inflammatory cytokines and restoration of intestinal microbial diversity in dextran sulfate sodium (DSS)-induced colitis. We believe that this innovative approach would offer a potential solution for improving colitis management and paving the way for tailored therapeutic interventions in gastrointestinal disorders.

A one-pot extraction-assisted d-galactose-to-d-tagatose isomerization strategy was proposed based on the selective extraction of d-tagatose by phenylborate anions. 4-Vinylphenylboronic acid was selected with high extraction efficiency and selectivity towards d-tagatose. The extracted sugars could be desorbed through a two-staged stripping process with the purity of d-tagatose significantly increased. In-situ extraction-assisted d-galactose-to-d-tagatose isomerization was implemented for the first time ever reported, and the effect of boron-to-sugar ratio (boron: sugar) was investigated. The conversion yield of d-tagatose at 60 °C increased from ∼ 39 % (boron: sugar = 0.5) to ∼ 56 % (boron: sugar = 1) but then decreased to ∼ 44 % (boron: sugar = 1.5). With temperature increased to 70 °C, the conversion yield of d-tagatose was further improved to ∼ 61 % (boron: sugar = 1.5), with the minimized formation of byproducts. Moreover, high purity (∼83 %) and concentrated d-tagatose solution (∼40 g/L) was obtained after sequential desorption. The proposed extraction-assisted isomerization strategy achieved improving the yield and purity of d-tagatose, proving its feasibility in industrial applications.

High-purity lactulose is mandatory for its medical uses and food applications. This work developed an efficient lab-scale strategy for the synthesis of high-purity lactulose by combining lactose-to-lactulose isomerization with simultaneous recovery of lactulose, which was conducted concurrently and semi-continuously in a boronate affinity adsorbent-packed column. The first step covers the boronate affinity adsorbent-based adsorption-assisted lactose-to-lactulose isomerization. Under optimized conditions, in situ selectively binding of the newly formed lactulose onto the boronate affinity adsorbent enables a much-enhanced lactulose yield up to 80.20% with the lowest byproducts yield of 6.30%. Afterward, over 90% of the adsorbed lactulose can be recovered through sequential desorption with purity >98%. The net outcome of the applied strategy was the yield of high-purity lactulose up to 72.31%, the highest value ever reported. Moreover, the packed column displayed excellent operational stability. The encouraging results validate the high potential of this approach in the sustainable production of high-purity lactulose.

BACKGROUND: Recovery of high-purity tea saponin (TS), a promising non-ionic surfactant with well-documented properties, is one of the major challenges to broadening its industrial applications. In this study, an innovative and sustainable strategy for the highly-efficient purification of TS was developed by using well-designed highly-porous polymeric adsorbents. RESULTS: The prepared Pp-A with controllable macropores (similar to 96 nm) and appropriate surface hydrophobic properties was found more favorable for achieving high adsorption efficiency towards TS/TS-micelles. Kinetic results showed the adsorption follows the pseudo-second-order model (R-2 = 0.9800), and the Langmuir model is more qualified to explicate the adsorption isotherms with Q(e-TS) similar to 675 mg g(-1). Thermodynamic studies revealed the monolayer adsorption of TS was an endothermic process that was conducted spontaneously. Interestingly, ethanol-driven desorption (90% v/v ethanol) of TS was rapidly (< 30 min) complete due to the possible ethanol-mediated disassembling of TS-micelles. A possible mechanism that involves the interactions between the adsorbents and TS/TS-micelles, the formation and disassembling of TS-micelles was proposed to account for the highly efficient purification of TS. Afterwards, Pp-A-based adsorption method was developed to purify TS directly from industrial camellia oil production. Through selective adsorption, pre-washing, and ethanol-driven desorption, the applied Pp-A enabled the direct isolation of high-purity TS (similar to 96%) with a recovery ratio > 90%. Notably, Pp-A exhibited excellent operational stability and is of high potential for long-term industrial application. CONCLUSION: Results ensured the practical feasibility of the prepared porous adsorbents in purifying TS, and the proposed methodology is a promising industrial-scale purification strategy. (c) 2023 Society of Chemical Industry.

Lactulose, a semisynthetic nondigestive disaccharide with versatile applications in the food and pharmaceutical industries, has received increasing interest due to its significant health-promoting effects. Currently, industrial lactulose production is exclusively carried out by chemical isomerization of lactose via the Lobry de Bruyn-Alberda van Ekenstein (LA) rearrangement, and much work has been directed toward improving the conversion efficiency in terms of lactulose yield and purity by using new chemo-catalysts and integrated catalytic-purification systems. Lactulose can also be produced by an enzymatic route offering a potentially greener alternative to chemo-catalysis with fewer side products. Compared to the controlled trans-galactosylation by β-galactosidase, directed isomerization of lactose with high isomerization efficiency catalyzed by the most efficient lactulose-producing enzyme, cellobiose 2-epimerase (CE), has gained much attention in recent decades. To further facilitate the industrial translation of CE-based lactulose biotransformation, numerous studies have been reported on improving biocatalytic performance through enzyme mediated molecular modification. This review summarizes recent developments in the chemical and enzymatic production of lactulose. Related catalytic mechanisms are also highlighted and described in detail. Emerging techniques that aimed at advancing lactulose production, such as the boronate affinity-based technique and molecular biological techniques, are reviewed. Finally, perspectives on challenges and opportunities in lactulose production and purification are also discussed.

Enzymatic isomerization of lactose into lactulose via cellobiose 2-epimerase (CE) could provide an eco-friendly route for the industrial production of lactulose, a valuable food prebiotic. However, poor substrate affinity for lactose and preference for epimerization over isomerization hinder this application. Previous studies on CE improvement have focused on random mutagenesis or active site rational design; little is known about the relationship between substrate binding and enzyme efficacy, which was hence the subject of this study. First, residues 372W and 308W were identified as key for disaccharide recognition in CEs based on crystal structure alignment of the N-acetyl-glucosamine 2-epimerase superfamily and site-directed mutation. This binding domain was then reshaped through site saturation mutagenesis, resulting in seven mutants with enhanced isomerization activity. The optimal mutant CsCE/Q371E had significantly enhanced substrate affinity (Km, 269.65 mM vs Km, 417.5 mM), reduced epimerization activity, and 3.3-fold increased isomerization activity over the original CsCE. Molecular dynamics simulation further revealed that substituting Gln-371 with Glu strengthened the hydrogen-bonding network and altered the active site-substrate interactions, increasing the substrate stability and shifting the catalytic direction. This study uncovered new information about the substrate binding region and its mechanisms and impact on CE catalytic performance, paving the way for potential commercial applications.

采集不同侵染阶段的苹果表层组织的拉曼光谱图像,对比标准品的拉曼光谱对拉曼峰进行解析,分别构建多糖、纤维素和果胶等主要成分分布的伪彩色图像,采用主成分分析(principal component analysis,PCA)结合线性判别算法建立5种优势腐败菌侵染苹果组织不同阶段的判别模型.研究发现,苹果细胞在1 645 cm-1和2 946 cm-1等拉曼位移处具有特征响应峰;多糖、纤维素和果胶在苹果细胞壁及细胞间隙中分布不均匀,且随着腐败菌侵染程度的加剧,其特征拉曼光谱峰强度呈下降趋势;PCA结果表明腐败菌侵染不同阶段的拉曼光谱具有聚类趋势,判别模型的校正集和预测集识别精度均达95％以上.结果表明,拉曼化学成像可以有效表征苹果腐败菌的侵染过程.

D-tagatose, one of the most valuable low-calorie rare sugars, is in huge market demand in the current food and medicine industries due to its excellent physiological functions. The production and recovery of high-purity tagatose from galactose isomerization presents two major challenges due to the exist thermodynamically limitation and their high structural similarity. Interestingly, the prepared macroporous polymeric boronate-affinity adsorbent (PBA-adsorbent) exhibited superior binding affinity towards tagatose than galactose. In a 1:1 galactose-to-tagatose binary solution, the PBA-adsorbent presented a much higher adsorption capacity towards tagatose (QTag = 53.94 mg/g) than galactose (QGal = 7.06 mg/g) and therefore enabled an excellent purification efficiency. Herein, a novel strategy for combining the PBA-adsorbent-based adsorption-assisted galactose-totagatose isomerization and simultaneous purification of tagatose, where the isomerization of galactose and the recovery of tagatose occur concurrently in the same PBA-adsorbent loaded column system, is presented. Through in situ selective capture of the newly formed tagatose, while leaving behind the galactose, the applied strategy enables an improved galactose-to-tagatose isomerization equilibrium with the yield of tagatose reaching up to 52.92%. Simultaneously, the adsorbed tagatose can be recovered efficiently via a two-stage sequential desorption process, which improves the tagatose purity to ~ 85% with a promising recovery ratio of 87.42%. Remarkably, both the prepared PBA-adsorbent and the applied strategy exhibited excellent operational stability. Through pHcontrolled desorption, the loaded PBA-adsorbent and the column system can be easily regenerated, well proving their good durability and recyclability in sustainable industrial applications. Furthermore, a possible mechanism involving the effect of boron-to-sugar ratio, the variation of boron intrinsic chemical states, and pH-responsive selective adsorption and sequential desorption was proposed to help understand how the applied PBAadsorbent based strategy facilitates the highly efficient galactose-to-tagatose isomerization.

Hierarchically structured protein-inorganic hybrid nanoflowers hold promise for efficient enzyme immobilization. Herein, a facile and rapid method to synthesize efficient lactulose-producing enzyme-metal hybrid biocatalyst was developed by using mutant E161D/N365P (EDNP) as the organic component and cobalt phosphate as the inorganic component. The synthesis conditions and stepwise formation of the EDNP@Co-3(PO4)(2) biocatalyst were systematically investigated. With the characterization of surface morphologies, chemical bonding states, and element compositions analysis, a possible growth mechanism has been proposed based on the affinity interaction between Co2+ and his-tagged EDNP, and the electrostatic interaction between Co2+ and PI43-. The resulting EDNP@Co-3(PO4)(2) showed effective encapsulation yield (39.70-57.22%) and promising activity recovery (43.08-62.88%). Interestingly, the specific activity expression of the EDNP@Co-3(PO4)(2) was about 1.1-fold higher than that of the free EDNP. The immobilized biocatalyst also exhibited greatly improved catalytic activity and stability towards pH (pH 5-9) and a broad range of temperatures (40-75 degrees C). More importantly, a second hybridization process was first applied to further improve the total encapsulation yield up to similar to 70%. Furthermore, the unique flower-like nanostructure enabled enhanced kinetic characteristics. Over 70% of enzyme activity was retained after eight catalytic cycles. All those results suggested that the prepared EDNP@Co-3(PO4)(2) has great potential in industrially lactulose bioproduction.

The purpose of this work was to reduce the oil content of potato chips by the pulsed electric field (PEF) pretreatment. The effects of PEF on oil content, color parameters, texture, microstructure, and acrylamide content of potato chips were investigated. The following appropriate pulse parameters were selected for pretreatment: the number of pulses was 2000, the pulse width was 5 mu s, the frequency was 20 Hz, and pulse direction was unidirectional pulse. The results showed that the electric field strength had a significant effect on the oil content and texture of potato chips. When pretreating the potato slices under the electric field strength of 10 kV/cm, the oil content of potato chips was reduced by 21.2%, and the hardness and crispness were significantly improved. The surface of the potato chips became smoother, and the porosity in the cross-section increased, which might be the reason for the reduced oil content of the potato chips. Finally, the potato chips prepared in current experiment had a low acrylamide content, approximately 10 ng/g (fresh weight). The above findings may provide useful information to guide the effective strategies for the practical application of PEF in reducing the oil content of fried foods.

Food pollution caused by mycotoxin seriously threatens the safety of human diet and has attracted extensive attention. Early and accurate detection of mycotoxin is essential to prevent further toxin spreading and contamination. A competitive aptasensor based on gold-silver core-shell structure contains signal molecule nanorods (ADANRs) and chitosan modified magnetic nanoparticles (CS-Fe3O4) was proposed to capture, enrich and obtain surface-enhanced Raman scattering (SERS) signals of patulin (PAT). The aptamer-modified CS-Fe3O4 was designed as the enrichment probe, and ADANRs fixed with the complementary chain of the aptamer on the surface were served as the capture probe. The detection limit of the competitive SERS aptasensor based on optimization of the ratio of two probes for PAT was 0.0384 ng/mL and the recovery rate (0.005% to 1.945%) was proved effective as a PAT detection tool for apple samples, which the required detection time was within 30 mins. The results showed that the nano-platform, held great promise in specific recognition and sensitive SERS detection for PAT.