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The effects of pressure (21.3, 41.3, 61.3, 81.3, and 101.3 kPa) and temperature (174–184 °C) applied during the post-frying centrifuge stage on the physico-chemical characteristics of atmospheric fried plantain chips were studied. Results showed that the surface temperature dropped very fast during the cooling process while the total oil content gradually increased. The oil uptake in the plantain chips increased by 7.7% after 9 min of post-frying cooling. Though an alteration in moisture and oil content was significantly affected (p < 0.05) by either vacuum pressure or temperature control applied during the post-frying centrifuge step, a higher reduction (p < 0.05) of moisture content by 79.1% and total oil content by 44.9% was observed when the combination of vacuum pressure (21.3 kPa) and temperature control was employed, comparing to the control of atmospheric pressure (101.3 kPa). Plantain chips centrifuged under vacuum pressure at 21.3 kPa without temperature control had higher total extractable phenolic acids and lower acrylamide content when compared to control sample. A reduction of pressure alone produced lighter color, higher crispness, and less volume shrinkage of plantain chips; however, no significant difference (p > 0.05) was observed among the samples centrifuged at different pressures. The application of vacuum pressure at 21.3 kPa together with temperature control for 5 min during the post-frying centrifuge stage was significantly effective (p < 0.05) in reducing moisture and oil content, while samples were less crispiness, shrunk more, and a higher bulk density.

The transformation of value-added solar-dried banana to banana syrup, which contains very high levels of fructooligosaccharides (FOS), is attractive. It has promising economic potential for the nutraceutical and functional food industry. In this study, the near-infrared (NIR) spectroscopy was used for the detection of 1-kestose (GF2), nystose (GF3), 1F-fructofuranosylnystose (GF4), and total FOS in solar-dried banana syrup in the spectral region of 4000–12,000 cm−1. Partial Least Squares (PLS) were applied to build the regression models. Considering the highest coefficient of determination (R2) and the lowest root mean square error (RMSE) of prediction, the prediction model of GF2 and GF3 yielded the greatest when original spectra at the optimization wavelength region was used. At the same time, the SNV procedure exhibited the best for the prediction model of GF4 and total FOS. Therefore, NIR spectroscopy with the PLS technique can be suitably applied for the rapid detection of FOS in solar-dried banana syrup.

This study addresses a significant gap in research by exploring the integration of nano-biochar (NBC) into porous concrete (PC) to enhance water purification capabilities while also evaluating its impact on the material's physical and mechanical properties. NBC was added in varying weights (0%–100%) to the binder material. Notably, beyond 10% NBC content, there was a significant reduction (p < 0.05) in porosity and compressive strength. Microstructural analyses using SEM, XRD, and FTIR revealed the incorporation of C–S–H within NBC pore structures. At 50% NBC content, substantial removal efficiencies (p < 0.05) were observed for manganese (Mn), nitrate (NO3−), total phosphorus (TP), and atrazine (AZ), reaching values of 97.4%, 93.9%, 97.3%, and 52.9%, respectively. Linear regression models revealed significant relationships between the degree of NBC enhancement and the efficiency of Mn and AZ removal. The logarithmic function provided the most accurate predictions for the quantity of NO3−and TP adsorbed by PC. These findings demonstrated that NBC-enhanced PC offers improved environmental remediation and provides guidelines for optimizing its composition for specific pollutants. Balancing mechanical and environmental performance, highlighting its potential as a sustainable construction material that meets both structural and pollution control needs is recommended.

This study aimed to investigate the feasibility of using the computer vision system (CVS) for monitoring color and surface oil content of durian chips during post-frying cooling. The results revealed the browning index values increased with cooling time, while surface oil content decreased. A high linear correlation of browning index as well as surface oil content and cooling time was observed (R2> 0.92). The image-processing technique can effectively be used to describe browning index and surface oil content of fried durian chips as it yielded a very high correlation (R2> 0.94). This technology exhibits great potential as a reliable, rapid, consistent, and non-destructive tool for process optimization and quality control of fried products.

This study aimed to classify the degree of adulteration of Pathumthani 1 in Khaw Dok Mali (KDML) 105 rice during up to 5 months’ storage. KDML 105 was mixed with Pathumthani 1 at seven different ratios (100:0, 95:5, 92:8, 90:10, 85:15, 80:20, and 0:100, w/w). The electronic nose (E-nose) was used to investigate the changes of aroma profiles in mixed rice, while GC–MS was conducted to determine the volatile compounds of each variety. The quantity of 2-acetyl-1-pyrroline (2-AP) was found to notably decrease to 42.1 and 48.7%, respectively, while hexanal increased by 20.3 and 26.6%, respectively, during 5 months of storage. The E-nose potentially exhibited the ability to discriminate the aroma profiles of two rice varieties at the ratio 100:0 and 0:100 during storage. However, the aroma profiles of mixed rice during storage were not clearly separated due to the alteration of volatile compounds in rice.

Freeze-drying represents a very effective method to significantly prevent loss of nutrients, especially heat-sensitive compounds. Moreover, osmotic dehydration is frequently applied prior to drying in order to facilitate moisture removal and improve quality. In the present study, the effect of osmotic pre-treatment combined with freeze-drying at different working pressures on microstructure, colour, and functional properties such as carotenoid contents, total phenolic contents (TP) and antioxidant activity in papayas was investigated. Osmotic pretreatment prior to freeze-drying resulted in increased yellowness, apparent density, and solid density, while carotenoids, TP, and antioxidant activity were lower compared to untreated samples. SEM images clearly showed that the effect of working pressure on the characteristic of dried papaya structure. Samples dried at working pressure of 9 and 77 kPa showed higher deformation with large cavities and dense dry layer when compared with those at 28 kPa. In addition, samples were significantly higher in lightness, redness, colour difference, and porosity when the working pressure was applied at 9 kPa. A reduction of working pressure had a negative effect on the retention of carotenoids, TP, and antioxidant activity in freeze-dried samples. It can be concluded that 28 kPa of pressure better conserved bioactive compounds and minimised structural deformation.

Colour change is a common physical phenomenon observed during drying, which need to be controlled since it directly affects consumer acceptance of dried products. This study aimed to investigate the feasibility of using computer vision, combined with laser light backscattering analysis at 650 nm in order to predict colour changes of papaya during drying. The results revealed that each image-processing factor obtained can potentially be used to describe every colour attribute change, except for chroma value. The multivariate correlations of measured backscattering parameters as well as the digital image properties were found to yield the best fitting for colour validations. Interestingly, the use of computer vision technique coupled with laser backscattering methods provides a reliable tool for quality control based on a rapid, consistent, and non-intrusive method for in-line quality measurement in established fruit drying processes.

A correction to this paper has been published: https://doi.org/10.1007/s11694-021-00939-1