Assessment of patulin adsorption efficacy from aqueous solution by water‐insoluble corn flour

Abstract

This study investigated water-insoluble corn flour (WICF) as a novel biosorbent for removing patulin from aqueous solutions, including contaminated fruit juices. Batch adsorption experiments were performed to assess the effect of granularity of WICF, adsorbent dosage, contact time, temperature, pH, and initial patulin concentration. The results showed that the maximum removal percentage of 92.21% was achieved at 37 8C, pH value of 4.0 in 100 mg/L patulin concentration for 25 hr. The adsorption data could be well fitted with the Freundlich isotherm model and the pseudo-first order model. Thermodynamic parameters indicated that mycotoxin adsorption is an endothermic and spontaneous process. Subsequently, scanning electron microscopy images showed obvious morphological changes in WICF after adsorbing patulin. Fourier transform infrared spectroscopy spectroscopic evidence demonstrated that the main functional groups involved in the adsorption were O-H, C 5 O and C-O groups. Practical applicationsPatulin was found as a contaminant in various fruit juices, which raised serious concerns about developing an effective and cheap adsorbent for detoxification of patulin toxin in fruit juice and their products. Water-insoluble corn flour was applied to strengthen the control of patulin for the first time. Results of this study indicated that water-insoluble corn flour has a strong ability to remove patulin from aqueous solutions and various fruit juices. Therefore, using water-insoluble corn flour as an adsorbent and combining the filtration process could be potentially applied in fruit juice industry for detoxification of patulin.

Synthesis of triethylene tetramine–modified water‐insoluble corn flour caged in magnetic chitosan resin and its adsorption application for removal of patulin from apple juice

“…Clearly, TETA‐WICF/MCR showed the best adsorption capacity of patulin, and this might be because more amino (–NH 2 ) groups can be covalently bonded by modification with TETA, as well as the existence of hydroxyl (–OH) groups in adsorbent, resulting in more adsorption sites for the excellent removal efficiency of patulin by TETA‐WICF/MCR. We also found that the patulin removal percentage considerably increased with an increase of adsorbent dosage, probably due to the accessibility of high affinity binding sites as the increase of the mass (Guo et al., 2018).…”

“…As apparent from FTIR spectroscopy spectrums, the characteristic peak of the pyranose ring around 896 cm −1 remained unchanged (Figures 2C–2E), implying that the structure of chitosan was not destroyed during the whole preparation process (Liao et al., 2016); and additional peaks located at 929 cm −1 (skeletal mode vibrations of a‐1,4 glycosidic linkage [C–O–C]), 761 cm −1 (C– stretching), and 706 cm −1 (skeletal modes, C–C stretching) occurred as a result of the immobilization of WICF (Guo et al., 2018); it was also found that another characteristic peak of 580 cm −1 , which corresponded to the Fe–O bond appeared in the spectrum of TETA‐WICF/MCR, indicating that the Fe 3 O 4 nanoparticles were successfully assembled on chitosan (Wang et al., 2017). In the specimen of C‐WICF/MCR (Figure 2C), the intensity of the peak at 1594 cm −1 weakened obviously, revealing that the amino groups decreased and the reaction between glutaraldehyde and amino groups was dominant.…”

“…In this study, △ H ° and △ S ° were found to be 14.242 kJ/mol and 63.536 J/(mol·K), respectively. The positive value of △ H ° indicated that the adsorption of patulin on the TETA‐WICF/MCR was endothermic (Guo et al., 2018). This observation was in excellent agreement with the results obtained from preliminary experimentation on the temperature effect of patulin adsorption.…”

“…The WICF with 20 to 40 mesh was prepared according to our previous study (Guo et al., 2018); 2.0 g of chitosan was completely dissolved in 50 mL of 2% (v/v) acetic acid solution via magnetic stirring to obtain a transparent viscous suspension. Then, 3.0 g of WICF and 0.5 g of Fe 3 O 4 were injected into the above solution under vigorously stirring.…”

“…A variety of adsorbents, such as Ca‐alginate–activated carbon beads, inactivated microorganism cell, thiourea‐modified chitosan resin, macroporous resin, magnetic chitosan, cross‐linked xanthated chitosan resin, and so forth, have been applied for patulin removal from juice‐pH simulation aqueous and contaminated fruit juices (Luo, Zhou, & Yue, 2017; Peng et al., 2016; Sajid, Mehmood, Yuan, & Yue, 2019; Wang, Lei, Yue, & Gao, 2015; Yue et al., 2013). In our previous work, water‐insoluble corn flour (WICF) as a biosorbent was prepared to remove patulin with varying degrees both in juice‐pH simulation aqueous and apple juice (Guo et al., 2018). Meanwhile, a lot of efforts have been made to functionalize WICF in order to further improve its adsorption capacity, mechanical strength, and separation efficiency.…”