Preparation and Characterization of Succinylated Nanoparticles from High-Amylose Starch via the Extrusion Process Followed by Ultrasonic Energy Abstract The aim of the present study was to obtain succinylated nanoparticles from high-amylose starch using a sequential method of extrusion and ultrasonic energy. Dynamic light scattering, degree of substitution, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy were employed to characterize the nanoparticles. The extrusion processing caused granular fragmentation and the succinylation of starch. Afterward, succinylated nanoparticles from the extruded starch were obtained with high yields using ultrasonication. Also, non-esterified nanoparticles were obtained to evaluate the succinylation effect. Succinylation increased hydrodynamic size (up to 329 nm) and ζ-potential values (up to − 62 mV) and improved the colloidal stability of succinylated nanoparticles compared to those of the non-esterified nanoparticles. Succinylated nanoparticles showed polyhedral morphologies, while non-esterified nanoparticles showed round-spherical and cubic morphologies. Moreover, all nanoparticulate systems showed a V61-type crystalline structure and an increased crystallinity. Using the sequential method of extrusion and ultrasonic energy made it possible to obtain succinylated nanoparticles from HAMS with size-controlled and desirable colloidal properties.

Novel Role of Ethanol in Delaying Postharvest Physiological Deterioration and Keeping Quality in Cassava Abstract Massive economic losses and the decrease in quality of cassava are caused by postharvest physiological deterioration (PPD). However, an effective solution remains limited. In this study, the role of ethanol in the PPD of cassava was investigated and highlighted. Exogenous ethanol delayed PPD and reduced the accumulation of reactive oxygen species, while increased the underlying activities of superoxide dismutase, catalase, peroxidase, and 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging. Moreover, exogenous ethanol increased the endogenous levels of ethylene and melatonin, all of which are negative regulators of PPD. Notably, this study found that exogenous ethanol reduced the degradation of starch, but enhanced ascorbic acid content and carotenoid content. In summary, these results revealed the novel role of ethanol in delaying PPD and improving the quality of cassava tubes without ethanol residue, suggesting an effective and promising way in cassava.

Vacuum Freezing of Coffee Extract Under Different Process Conditions Abstract This research work was focused on evaluating the vacuum freezing (VF) of coffee extract under different process conditions as well as on its comparison with air freezing (AF) and contact freezing (CF). Regarding VF, extract concentration (10 to 40 oBrix) did not affect freezing time (for sufficiently high pressure drop rates), whereas extract layer thickness had significant impact, with 50% higher process times for samples arranged in 6-mm-thick layers in comparison with 4-mm-thick arrangements. Moreover, reduction of pressure drop rate (from 0.57 to 0.37 kPa s−1) caused an increase of up to 5 times of VF time. In comparison with AF and CF, VF led to significantly smaller freezing times along with higher mass losses (of 26–43% contrasting with 1–2% losses for AF and CF). This fact, allied to the extremely porous structure formed during VF, makes this method particularly interesting for soluble coffee production by freeze drying.

The Role of Glycogen Synthase Kinase-3 in Gibberellic Acid-Induced Chilling Tolerance and Defense Response in Postharvest Peach Fruit Abstract The induction of chilling tolerance and defense response by glycogen synthase kinase-3 (GSK-3) under gibberellic acid (GA3) treatment in peach fruit was explored at 4 °C up to 28 days. The fruits were treated with exogenous GA3 and bikinin (GSK-3 inhibitor). Results showed that exogenous GA3 alleviated chilling injury, and upregulated endogenous GA3 content in peach fruit. Furthermore, GSK-3 expression was activated by exogenous GA3 treatment. GA3 also upregulated gene expression of superoxide dismutase, peroxidase, catalase, glutathione reductase, glutathione S-transferase, and ascorbate peroxidase. Additionally, GA3 enhanced gene and protein expression of small ubiquitin-like modifier and gene expression of methionine sulfoxide reductase, and weakened gene expression of lipoxygenase and phospholipase D. These above impacts stimulated by exogenous GA3 were blocked by the addition of bikinin. Overall, GSK-3 was involved in stimulation of chilling tolerance and defense response under GA3 treatment in postharvest peach fruit.

Extraction and Characterization of Phenolic Compounds from Bamboo Shoot Shell Under Optimized Ultrasonic-Assisted Conditions: a Potential Source of Nutraceutical Compounds Abstract The extraction and characterization of bioactive compounds from bamboo shoot shell was performed under ultrasonic-assisted extraction (UAE) along with UPLC-Triple-TOF/MS analysis. Under optimized UAE conditions (ethanol concentration (58%), liquid to solid ratio (24 mL/g), extraction temperature (59 °C), and sonication time (29 min)), total phenolic content (TPC) was recorded highest as 85.3 mg GAE/g DW, while DPPH and FRAP antioxidant activities were 77 μmol AAE/g DW and 33 μmol AAE/g DW, respectively. Using UPLC-Triple-TOF/MS analysis, fifteen phenolic acids, seven flavonoids, nineteen organic acids, two iridoid glucosides, and one neoglinan were identified. Among them, p-coumaric acid (119 μg/g DW), chlorogenic acid (87 μg/g DW), rutin (39 μg/g DW), and ferulic acid (17 μg/g DW) were found to be the most abundant phenolic compounds. Furthermore, compounds including phenolic acids (3-p-coumaroylquinic acid, cryptochlorogenic acid, 3-O-feruloylquinic acid, 5-O-feruloylquinic acid, 3-O-caffeoylshikimic acid, 5-p-coumaroylquinic acid, 1,3-dicaffeoyl quinic acid, 3,5-dicaffeoyl quinic acid), flavonoids (schaftoside/c-hexosyl-c-pentosylapigenin, apigenin 6,8-di-C-α-l-arabinopyranoside, kaempferide 3-O-α-l-rhamnopyranosyl(1->6)-β-d-glucopyranoside, 6-C-β-d-glucopyranosyl-8-C-α-l-arabinopyranosylchrysin, narcissin), some organic acids, iridoid glucosides, and neolignan were also detected for the first time from bamboo shoot shell extract. The present study revealed that bamboo shoot shell extract contains a larger number of nutraceutically active compounds which can be further utilized by food and nutraceutical industries.

Design and Optimization of a Microchip Operating at Low-Voltage Pulsed Electric Field for Juice Sterilization Abstract Microchip has been widely used in the biochemical field, but it is rarely applied in the food area. In this paper, an optimal microelectrode model was obtained via the improved evolutionary structural optimization (ESO) method, the effect of topological parameters on the sterilization efficiency was clarified, and the optimized microchip was applied to the sterilization of blueberry juice to verify its feasibility. The analysis of finite element method (FEM) results showed that planar comb teeth (PCT) form, quadrilateral electrode structure with 100-μm electrode spacing, was the ideal model for the microchip. On the basis of the optimal electrode model, a continuous low-voltage pulsed electric field (LPEF) experimental platform was built. Under 400 V and 0.2-ms conditions, LPEF processing better preserved vitamin C, anthocyanin, total phenolics content, and color parameters while reducing microbial counts in blueberry juice significantly. During 30 days of storage at 4 °C, LPEF-treated juices had more vitamin C, anthocyanin content, and brighter color under the premise of ensuring microbiological safety, compared with high temperature short time (HTST) and pulsed electric field (PEF)-treated juices. This study provides theoretical and technological support for the widespread use of LPEF technology in the application of a non-thermal processing technique for food.

3D Extrusion Printing and Post-Processing of Fibre-Rich Snack from Indigenous Composite Flour Abstract This study focused on developing nutritious 3D-printed snacks from composite flour prepared from barnyard millet, green gram, fried gram, and ajwain seeds. The work evaluated extrusion printability of the high-fibre, high-protein composite flour. Optimised process parameters that gave best resolution and stability are nozzle diameter of 0.84 mm, nozzle height of 0.63 mm, printing speed of 2400 mm/min, extruder motor speed of 300 rpm, and movement speed of X/Y and Z axis of 6000 mm/min and 1000 mm/min, respectively. 3D-printed objects were post-processed by deep frying, hot-air drying followed by deep frying and microwave drying. With proximate analysis of the post-processed 3D-printed foods, we conclude that microwave drying could better retain nutrients, while ensuring minimal changes in colour and textural properties, as compared with other post-processing methods. All post-processed samples were acceptable in terms of sensory attributes; the developed snack has the potential to be commercialised. This work explains the successful development of nutritious 3D-printed snacks from diverse plant sources, importantly, with emphasis on the development of high-fibre foods with good consumer acceptance.

Candelilla Wax-Based Coatings and Films: Functional and Physicochemical Characterization Abstract Active coatings and films made from pectin, candelilla wax, aloe mucilage, and glycerol were functionalized with an extract rich in polyphenols from Larrea tridentata (Polyphenol Larrea extract: PLE) leaves at different concentrations (320 to 920 ppm). Antimicrobial capacity was evaluated on avocados by the inoculation of spores from phytopathogenic fungi Colletotrichum gloesporioides and Alternaria alternata. Coatings with 920 ppm of PLE presented the major antimicrobial capacity leading to 22.0 ± 0.4% of endocarp damage for C. gloesporioides and 24.5 ± 0.6% for A. alternata when compared to uncoated (control) avocados (44.8 ± 5.0% for C. gloesporioides and 47.9 ± 9.3% for A. alternata). The coating formulation with 920 ppm of PLE, which presents the highest antimicrobial capacity, was chosen for further evaluation and characterized. The coatings were evaluated in terms of stability, charge, pH, viscosity, and density, and some authors reported stability at 7 days. The films were evaluated by scanning electronic microscopy (SEM), X-ray diffraction, Fourier transformed infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and contact angle measurements. The surface topography shows that the presence and increase of PLE concentrations leads to a higher roughness of the films, and by FTIR was possible to observe the effect of the PLE incorporation on the functional groups of the film matrix. Contact angle was not affected by the incorporation of PLE in the films. The developed bioactive coating is effective to control endocarp damage by fungus invasion and thus protect avocados during storage.

Icariin as a Preservative to Maintain the Fruit Quality of Banana During Postharvest Storage Abstract Banana is a tropical fruit with good palatability and multiple health benefits. However, the fruit quality is readily deteriorated during postharvest storage. In this work, icariin was used to treat banana to maintain the fruit quality. NMR spectroscopy was applied to analyze the effect of icariin on the metabolite profiles of banana. It was found that the fruit quality of banana was well maintained after icariin treatment. The data of 1D and 2D NMR spectra revealed the composition of metabolites, whose contents greatly varied during storage. The first principal components included ethanol, acetic acid, saponin b, salsolinol, dopamine, glucose, and linoleic acid. After icariin treatment, the conversion of starch to α-d-glucose and β-d-glucose was delayed, and the production of γ-aminobutyrate, glutamine, and alanine increased. These results indicated that icariin could effectively maintain the fruit quality and delay the senescence of banana. Graphical Abstract

Spontaneous Color Change of 3D Printed Healthy Food Product over Time after Printing as a Novel Application for 4D Food Printing Abstract A four-dimensional healthy food product was fabricated, in which 3D printed anthocyanin-potato starch (PS) gel changed its color over time to an attractive color (the 4th dimension). The color changed not only when sprayed the 3D product with different pH solutions but also independently as a response to an internal pH stimulus from another part inside the printed multi-material product. To achieve this, two parts of the gel system were combined, one part was from anthocyanin-PS gel and another part from lemon juice gel. In addition, the color change of anthocyanin-PS gel was also assessed after spraying with different pH solutions at different concentrations of PS and anthocyanin. Color changes were evaluated in terms of lightness (L*), redness (a*), and blueness (b*) using a colorimeter. The color stability of the 4D food product was examined for 24 h after printing. Moreover, a sensory evaluation test was performed to assess the consumer acceptance of the 4D food product. The printed samples sprayed with pH solutions 2, 2.5, 3, and 3.5 showed significant differences (p ≤ 0.05) in color at all PS and anthocyanin concentrations. However, pH samples 4, 4.5, and 5 did not show any visible difference in color after treatment compared to control samples. Furthermore, the color of the 3D printed anthocyanin-PS gel in model (A) gradually changed from purple to red over time during and after the printing process. On the contrary, the 3D printed anthocyanin-PS gel in model (B) did not show any noticeable color change over time after printing. This paper presents a novel application for 4D printing in the food field, which is very important for the food industry to fabricate a healthy product with attractive colors.