Effect of carbonation and ultrasonication assisted hybrid drying techniques on physical properties, sorption isotherms and glass transition temperature of banana (Musa) peel powder

Ultrasound assisted extraction of red cabbage and encapsulation by freeze-drying: moisture sorption isotherms and thermodynamic characteristics of encapsulate

In the present study encapsulation of ultrasound assisted red cabbage extract was carried out using four different carrier agents such as maltodextrin, gum arbic, xanthan gum, and gellan gum. Among the four hydrocolloids investigated, maltodextrin was found to have the least destructive effect on anthocyanin content (14.87 mg C3G/g dw), TPC (54.51 ± 0.09 mg GAE/g dw), TFC (19.82 Mg RE/g dw) and antioxidant activity (74.15%) upon freeze-drying. Subsequently a storage study was conducted using maltodextrin as carrier agent at 25-50 °C. The Clausius-Clapeyron equation was used to evaluate the net isosteric heat (qst) of water adsorption. The differential entropy (ΔS) and qst decreased from 82.298 to 38.628 J/mol, and 27.518 kJ/mol to 12.505 kJ/mol, respectively as the moisture content increased from 2 to 14%. The value of isokinetic energy and Gibb's free energy were found to be 364.88 and - 1.596 kJ/mol for freeze dried red cabbage.

Graphical abstract

The Influence of Pulsed Electric Field and Air Temperature on the Course of Hot-Air Drying and the Bioactive Compounds of Apple Tissue

Drying is one of the oldest methods of obtaining a product with a long shelf-life. Recently, this process has been modified and accelerated by the application of pulsed electric field (PEF); however, PEF pretreatment has an effect on different properties—physical as well as chemical. Thus, the aim of this study was to investigate the effect of pulsed electric field pretreatment and air temperature on the course of hot air drying and selected chemical properties of the apple tissue of Gloster variety apples. The dried apple tissue samples were obtained using a combination of PEF pretreatment with electric field intensity levels of 1, 3.5, and 6 kJ/kg and subsequent hot air drying at 60, 70, and 80 °C. It was found that a higher pulsed electric field intensity facilitated the removal of water from the apple tissue while reducing the drying time. The study results showed that PEF pretreatment influenced the degradation of bioactive compounds such as polyphenols, flavonoids, and ascorbic acid. The degradation of vitamin C was higher with an increase in PEF pretreatment intensity level. PEF pretreatment did not influence the total sugar and sorbitol contents of the dried apple tissue as well as the FTIR spectra. According to the optimization process and statistical profiles of approximated values, the optimal parameters to achieve high-quality dried apple tissue in a short drying time are PEF pretreatment application with an intensity of 3.5 kJ/kg and hot air drying at a temperature of 70 °C.

Effect of fermentation with Lactobacillus fermentum FL-0616 on probiotic-rich bean powders

Plant-based diets have received considerable attention for balancing human health and environmental sustainability. This study investigated the effects of fermentation with Lactobacillus fermentum FL-0616 on probiotic-rich mung bean, chickpea and tiger skin kidney bean powders. A particle size distribution experiment showed that the particle size of probiotic-rich bean powder was significantly reduced and the specific surface area was increased. This was critical for improving the dissolution rate, wettability and dispersibility. Simultaneously, the angles of repose and slide of the fermented bean powder were significantly reduced. Scanning electron microscopy confirmed that particle size of the bean powder decreased and became more uniform after fermentation. The results of dynamic and static rheology jointly demonstrated that fermentation improved the flowability of probiotic-rich bean powder, which was related to its decreased particle size. This study provides a technical foundation for the deep processing of bean resources.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05668-5.

Evaluation of ultrasonication and carbonation-ultrasonication assisted convective drying techniques for enhancing the drying rates and quality parameters of ripe and raw banana (Musa) peel

Raw and ripe banana (Musa Cavendish) peel slices were dried by application of ultrasonication (U) and carbonation-ultrasonication (CU) as pre-treatments for tray drying (T) at 60 °C. Lesser drying time and higher diffusivity was noticed in CU + T dried samples followed by U + T and T dried samples. Model 'Wang and Singh' was identified as the excellently fitting model to experimental data. SEM images of dried samples revealed the microchannels formation due to U treatment, which were more couloir after CU treatment. Water and oil holding capacity (WHC and OHC) for raw peel powders was higher than ripened peel powders at 40, 60 and 80 °C. WHC and OHC increased significantly after U + T drying or CU + T drying as compared to T drying for ripe and raw peel powder samples. Back extrusion force (BEF) varied from 67.42 to 69.22 N and from 84.6 to 86.02 N for ripe and raw peel samples respectively. Given treatments resulted in lesser colour change and Browning Index. But U + T or CU + T treatment did not affect BEF significantly. CU + T was deemed to be the appropriate drying technique for ripe and raw banana peel drying.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05535-9.

Effect of Maltodextrin and Soy Protein Isolate on the Physicochemical and Flow Properties of Button Mushroom Powder

In this investigation, the effect of different drying techniques, such as freeze-drying and cabinet drying, with two different carrier agents, such as maltodextrin (MD) and soy protein isolate (SPI), at different levels (10, 15, and 20%) on button mushrooms has been revealed. The results showed that the button mushroom powders (BMPs) formulated with SPI as a carrier agent had significantly higher powder yield, hygroscopicity, L *, a *, and b * values, whereas BMP formulated with MD had significantly higher water activity, solubility index, tapped density, bulk density, and flowability. The highest retention of bioactive compounds was reported in freeze-dried mushroom powder compared to cabinet dried powder using SPI as a carrier agent. Fourier transform infrared (FTIR) analysis confirmed that certain additional peaks were produced in the mushroom button powder-containing SPI (1,035-3,271 cm-1) and MD (930-3,220 cm-1). Thus, the results revealed that SPI showed promising results for formulating the BMP using the freeze-drying technique.