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A method named imprint paper spray ionization mass spectrometry (imprint-PSI-MS) has been developed and employed for the determination of pungency of peppers. A pepper fruit was cut into a triangular shape, deposited onto a triangular paper, and compressed by a homemade press tool aiming to imprint and transfer the pepper constituents onto the paper surface. Subsequently, the triangular paper was submitted to conventional PSI-MS analysis. Twelve peppers were analyzed, ranging from highly pungent to lowly pungent taste. Pepper pungency values from the Scoville scale (in Scoville heat units, SHU) were compared with the ion intensities of the capsaicin and dihydrocapsaicin compounds obtained from the imprint-PSI-MS analysis, and a correlation coefficient of 0.97 was achieved. In addition, the ion intensities of a sugar compound were monitored in all peppers, and the results were compared with the Scoville scale. Low sugar ion intensities were detected in pungent peppers, while high ion intensities were achieved in low-pungent peppers, suggesting that the pepper pungency may be determined by inversely relating pungency to sugar contents. This work demonstrates the utility of the imprint-PSI-MS method to perform rapid qualitative analyses of peppers and estimate the pungency by monitoring the pepper metabolites. Graphical abstract.

Thermostable cellulases have wide variety of applications and distinctive advantages, but their low titer becomes the hurdle in their commercialization. In the present work, an assessment of optimum levels of significant factors (temperature, moisture ratio, inoculum size, and ammonium sulfate) and the effect of their interactions on production of thermostable CMCase, FPase, and β-glucosidase by Thermoascus aurantiacus RCKK under solid-state fermentation (SSF) was carried out using central composite design (CCD) of response surface methodology (RSM). The study revealed 33, 13, and 8 % improvement in FPase, CMCase, and β-glucosidase production, respectively. Moreover, crude cellulase from T. aurantiacus RCKK efficiently hydrolyzed office waste paper, algal pulp (Gracillaria verulosa), and biologically treated wheat straw at 60 °C with sugar release of about 830 mg/ml, 285 mg/g, and 260 mg/g of the substrate, respectively. The thermostable enzyme from T. aurantiacus RCKK holds potential to be used in biofuel industry.

Sixty fungal cultures were isolated from agricultural soil, industrial soil, forest canopy soil having decomposed leaf litter and compost samples collected from different regions of India. Fifteen fungal cultures were selected qualitatively for the production of xylanase and cellulases and were identified employing ITS, NS and MNS primers. The enzyme cocktail consisting of 3811 IU g(-1) of xylanase and 9.9 IU g(-1) of cellulase from Trichoderma longibrachiatum MDU-6 was selected quantitatively for the deinking of diverse paper wastes. The enzyme production increased two fold when produced at tray level in comparison with flasks. The enzyme cocktail was effective in the deinking of old newspaper samples with significant removal of chromophores, phenolics and hydrophobic compounds and less sugar loss. While in case of examination papers and laser printed papers, ink removal was not very significant. Moreover, the sugar loss was significantly high in case of examination papers. The deinking results were further confirmed with FTIR analysis. Deinked newspaper pulp sample shows brightness of 52%, which was 9.6% high than its control sample. The ERIC value for deinked newspaper pulp was found to be 655.9 ppm. Thereafter, the deinked newspaper pulp was examined under light microscope after differential staining with safranin and malachite green and also examined under scanning and transmission electron microscope, which revealed fibrillation and perforation.

Peaches are known for their palatable flavor and abundant nutrients. However, peaches are perishable, and the existing preservation techniques for peaches are still immature. To further extend the shelf life and prevent nutrient loss of perishable peaches under ambient temperature in summer (approximately 25–32 °C), we conducted experiments wrapping peaches (Prunus persica cv ‘Baihua’) in single- and composite-treated vegetal fibrous papers that contained calcium carbonate, phytic acid, Na-alginate and vitamin C. The pathogenic fungi that primarily caused peach decay during storage belonged to the genera of Penicillium, Botrytis, Aspergillus, Alternaria, and Rhizopus. After analyzing quality attributes, including weight loss, firmness, soluble sugar content, respiration rate, relative electric conductivity, malonaldehyde content, peroxidase activity and the decay index, we proved that vitamin C within the preservative paper greatly contributes to peach preservation. Combined with phytic acid and Na-alginate, the composite vitamin C preservative papers played significant roles in delaying fruit senescence, and 0.4% (w/v) vitamin C preservative paper with 1% Na-alginate could maintain quality and extend shelf life with the best effect. This preservation technique significantly postponed the respiration peak by 2–3 days and is a significant contribution to contemporary commercial production.