Effects of fermentation on the structures of yellow compounds in citrus pomace.

To enhance the stability and light resistance of the yellow compounds in citrus pomace, our study successfully isolated and purified five compounds using ultrasonic-assisted extraction and column chromatography. The identified compounds include methyl linoleate, (2-ethyl)hexyl phthalate, 1,3-distearoyl-2-oleoylglycerol, 6,6-ditetradecyl-6,7-dihydroxazepin-2(3H)-one, and n-octadeca-17-enoic acid. The monomers extracted from fresh pomace, compounds 1 and 2, exhibit structural similarities to flavonoids and carotenoids.

Optimization of limonin invertase production by scaling up Aspergillus tubingensis UA13 fermentation to a 5-l scale.

The enzymatic approach is a highly effective and the major scientific method to eliminating bitter components in citrus-derived products nowadays. Microbial production of limonin invertase stands out due to its pivotal role in the removal of the bitter substance, limonin. The optimization of fermentation parameters and the study of scale-up fermentation are imperative for product commercialization.

Effects of different processing methods on the chlorophyll structure in kiwifruit.

Kiwifruit puree was treated with high and normal temperatures and pressures as independent variables to determinate the structural changes of chlorophyll derivatives. Two groups of colored elution samples were identified as single component compounds by High Performance Liquid Chromatography (HPLC). In addition, the structures of the two compounds were identified and analyzed by High Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR).

Optimization of process parameters for naringinase production by UA13 and pilot scale-up study.

To improve the naringinase production of UA13, shorten the fermentation period, and verify its industrial application value, naringinase production conditions were optimized, and 5 L scale-up study in stirred tank bioreactor was carried out. Parameters, including carbon, nitrogen sources and inducer, optimal seed age, inoculum amount, temperature and pH, were adjusted and optimized in shaking flask. Keeping pH at the optimal value 6 in bioreactor, dissolved oxygen was monitored during the fermentation and the optimal stirring rate was investigated.

Effects of lard on the formation of volatiles from the Maillard reaction of cysteine with xylose.

Background: The presence of lipid oxidation products in the Maillard reaction pathway is of particular interest today. The objective of this study was to investigate the effect of lard and its oxidation products on the formation of volatiles from cysteine and xylose model systems.

Results: Headspace volatiles generated in reaction mixtures were examined by solid-phase microextraction in combination with gas chromatography-mass spectrometry.