Effect of ultrasonic power on drying process and quality properties of far-infrared radiation drying on potato slices

et al. 2020

Antioxidants

It has been revealed by us that superoxide scavenging is a new activity of trypsin. In this study, the synergistic mechanisms of trypsin and superoxide dismutases (SODs) were evaluated in Hylocereus undatus (pitaya). Trypsin significantly improved the storage quality of H. undatus, including weight loss impediment and decrease of cellular injury. The regulatory mechanisms of 16 SOD genes by trypsin were revealed using transcriptomic analysis on H. undatus. Results revealed that important physiological metabolisms, such as antioxidant activities or metal ion transport were induced, and defense responses were inhibited by trypsin. Furthermore, the results of protein-protein interaction (PPI) networks showed that besides the entire ROS network, the tiny SODs sub-network was also a scale-free network. Cu/Zn SODs acted as the hub that SODs synergized with trypsin during the storage of H. undatus.Trypsin is a widely used protease. It has been confirmed that trypsin significantly impacts on the free radical scavenging activities of flavonoids [8]. Our previous results also showed that trypsin scavenges superoxide anions (O 2 • − ) and protects cells [9].In the area of phytopathology, transcriptomic analysis has been successful used on lots of plants [10][11][12][13]. However, few of transcriptomic works have been focused on the preservation of fruits. The mechanisms of betalain biosynthesis have been investigated in H. undatus [2], and the concision analysis of antioxidant system induced by trypsin has also been investigated in our previous paper [14]. Considering the superoxide scavenging activity of trypsin, the function and synergistic mechanisms of trypsin with SODs impact on the quality of H. undatus during storage is an interesting work. The mechanisms of postharvest quality of fruits still need more works.Protein-protein interaction (PPI) networks analyses help us to figure out the regulatory mechanisms of proteins [15]. Plugins of Cytoscape, including NetworkAnalyzer, Molecular Complex Detection (MCODE), and cytoHubba, could score and rank the nodes or obtain clusters in the PPI network [16].In the current work, the regulatory mechanisms of trypsin on the H. undatus by cooperating with SODs were investigated. The changes in expression of SODs of H. undatus peels were analyzed. Analyses of gene ontology (GO) and KEGG enrichment of ROS or SOD related genes were performed, and the PPI network of ROS related genes and sub-network of SODs and their first neighbors were constructed. The hub genes of SODs regulated by trypsin during storage were further screened by cytoHubba and MCODE of cytoscape.

Section: Discussionmentioning

confidence: 63%

Transcriptomic Analysis Reveals Cu/Zn SODs Acting as Hub Genes of SODs in Hylocereus undatus Induced by Trypsin during Storage

Pang

et al. 2020

Antioxidants

“…Increasing ultrasound power promote a rise in drying rate ( p < .05), which is related to the cavitation and mechanical effects after ultrasound penetrated into the material and produced high‐frequency vibration. On the one hand, rapid and high frequency vibration, along with expansion and contraction of internal tissue caused by the mechanical effect increase the energy of water molecules and decrease water adhesion, thus enhancing mass transfer (Vallespir et al., 2019; Xi et al., 2020). On the other hand, the cavitation effect could generate enormous tiny cavities with violent kinetic energy and compression energy inside potato tissue (Liu, Zeng, Hu, & Sun, 2020; Sun, Liu, et al, 2017).…”

Section: Resultsmentioning

confidence: 99%

“…It is also illustrated that the drying rates of UCAD on potato showed a continuous downward trend, which suggests that the dehydration process was controlled by internal diffusion. It was reviewed that quick diffusion and turbulence of internal moisture promoted by ultrasound could remarkably speed up the potato drying process (Xi et al., 2020). When the moisture content of potato slices was high, its sharp reduction was followed by increasing ultrasound power at the same cold air temperature.…”

Section: Resultsmentioning

confidence: 99%

“…Ultrasound strengthening technology is an emerging and promising method which can effectively intensify mass transfer and water diffusion inside dried materials (Kaveh, Jahanbakhshi, Abbaspour‐Gilandeh, Taghinezhad, & Moghimi, 2018; Liu et al., 2017). Xi, Liu, Guo, and Hu (2020) stated that the mechanical and cavitation effects of the assisted ultrasound during drying process could effectively reduce the resistance of water migration in materials and promote internal water diffusion without obvious thermal effect. Liu, Sun, et al (2019) verified that direct contact ultrasound application in the drying of pear would cause loose microstructure and save drying time significantly.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Drying characteristics and optimization of ultrasound‐strengthened cold air drying combined with sequential far‐infrared radiation drying on potato

Zhang

Sun

et al. 2020

J Food Process Preserv

Self Cite

To improve the dehydration rate and product quality of potatoes, a new strategy utilizing ultrasound‐strengthened cold air drying combined with sequential far‐infrared radiation drying (UCAD‐FIRD) was proposed. The results prove that UCAD greatly promotes dehydration speed, and stronger ultrasound power results in higher drying rate. Compared with UCAD process, UCAD‐FIRD drastically shortens the required drying time. Potato slices dried by UCAD‐FIRD retain more nutrients compared with those dried by UCAD alone, exhibited by lower color variations and a greater rehydration ratio. For example, total phenol content and Vitamin C content rise first and then, decline but still remain at a high level. The Gray Correlation Analysis is applied to obtain the best experimental group as follows: cold air temperature of 15°C, radiation temperature of 140°C, ultrasound power of 60 W. Therefore, the drying strategy of UCAD‐FIRD can remarkably accelerate the drying rate and simultaneously improve the product quality. Practical applications Cold air drying (CAD) can well preserve the product quality due to low drying temperature. However, too long dehydration inevitably restricts its application, so some effective auxiliary measures can be applied to promote mass transfer in CAD to improve the dehydration process. In this study, we proposed a UCAD‐FIRD drying strategy, in which contact ultrasound strengthening technology was applied in CAD to significantly accelerate the internal mass transfer of early drying process, subsequently, FIRD was applied to replace UCAD at a certain conversion point to further accelerate water removal in latter stage with lower moisture content. The UCAD‐FIRD strategy could achieve both shorter dehydration time and better product quality, comparing with single CAD and UCAD. Therefore, UCAD‐FIRD is a promising and practical drying strategy for fruits and vegetables which have great internal mass transfer resistance and thermo‐sensitivity.

“…In the top 2 pathways regulated by trypsin, 11 and 7 genes were involved in "Phenylpropanoid biosynthesis (map00940)" and "MAPK signaling pathwayplant (map04016)". As we know, peroxidase (POD) is the key enzyme of the last process of lignin synthesis [16,17]. In map00940, Guaiacyl lignin, 5-hydroxy-gualacyl lignin, syringyl lignin and p-hydroxy-phenyl lignin were regulated by POD (Fig.…”

Section: Discussionmentioning

confidence: 99%

Transcriptomic analysis reveals hub genes and subnetworks related to ROS metabolism in Hylocereus undatus through novel superoxide scavenger trypsin treatment during storage

Pang

et al. 2020

Preprint

Background: It was demonstrated in our previous research that trypsin scavenges superoxide anions. In this study, the mechanisms of storage quality improvement by trypsin were evaluated in H. undatus. Results: Trypsin significantly delayed the weight loss and decreased the levels of ROS and membrane lipid peroxidation. Transcriptome profiles of H. undatus treated with trypsin revealed the pathways and regulatory mechanisms of ROS genes that were up- or downregulated following trypsin treatment by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses. The current results showed that through the regulation of the expression of hub redox enzymes, especially thioredoxin-related proteins, trypsin can maintain low levels of endogenous active oxygen species, reduce malondialdehyde content and delay fruit aging. In addition, the results of protein-protein interaction networks suggested that the downregulated NAD(P)H and lignin pathways might be the key regulatory mechanisms governed by trypsin.Conclusions: Trypsin significantly prolonged the storage life of H. undatus through regulatory on the endogenous ROS metabolism. As a new biopreservative, trypsin is highly efficient, safe and economical. Therefore, trypsin possesses technical feasibility for the quality control of fruit storage.