Band 21, Heft 9

This study investigated effects of mold fermentation on the texture and flavor of soy-nut cheese analogs (SNCA) using Mucor wutungkiao (SNCA-M), Rhizopus oryzae (SNCA-R), and their combination (SNCA-M+R) over 20-day fermentation period. The results found that all cheese analogs showed decreasing trends in protein content, fat content, pH, springiness, and cohesiveness throughout fermentation. Notably, the moduli, hardness, and chewiness peaked on day 3 before declining. The rate of these changes was more pronounced in SNCA-M+R than in SNCA-M or SNCA-R. All samples achieved their higest sensory scores on day 5 of fermentation. At this stage, the fermented analogs showed significantly higher free amino acid (FFA) content and volatile flavor compound concentrations, along with reduced levels of beany flavor substances compared to unfermented controls. Among the variants, SNAC-M+R displayed the highest sensory score and FFAs content, as well as the lowest concentration of beany flavor compounds.

Gucong tree leaves ( Camellia sinensis var. assamica ) are conventionally processed into white or oolong tea, with limited application in green tea production. This study aims to investigate and elucidate the quality and aroma characteristics of green tea manufactured from Gucong tree leaves, focusing on the influence of bud-to-leaf ratio and thermal processing parameters (drying and roasting) on aroma development. The volatile substances, including both free and bound forms, were analyzed using the headspace solid–phase micro-extraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). And the aroma characteristics were further examined through the multivariate statistical analyses, including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and the odor activity value (OAV) calculations. A total of 51 volatile compounds were identified in fresh leaves and derived green tea, with 11 key aroma-active compounds discerned. Geraniol and linalool emerged as the most abundant constituents, while alcohols dominated the volatile fraction. Notably, there were 11 compounds, including 1-octen-3-ol, geraniol, and benzene-acetaldehyde significantly contributed to the overall aroma. Aroma radar plots further defined Gucong green tea by its distinct floral, sweet, and green notes. The origin of the raw materials and the drying processes were identified as the critical factors influencing the generation of the green aroma. These findings significantly enhance our understanding of the production and processing of Gucong leaves.

Pineapple has high emulsifying capacity and acerola has high healthy bioactive compound levels. The mixture of these fruits can be used in the preparation of functional powdered beverages through freeze-drying. Physicochemical, rheological, thermal and colorimetric parameters and bioactive compounds were measured and the microstructures of the powders were visualized by scanning electron microscopy. The freeze-dried pulps had an attractive color, high hygroscopicity (>27 g/100 g), low water activity (≤0.334 ± 0.009), glass transition temperature ranging from 1.46 to 3.89 °C and microstructure strongly porous. Both fresh and rehydrated mixed pulps showed the rheological behavior of a non-Newtonian pseudoplastic fluid. The pineapple pulp:acerola pulp ratio influenced significantly the variables analyzed. Higher contents of bioactive compounds (ascorbic acid, total phenolic, anthocyanin, antioxidant activity) after freeze-drying and storage were obtained increasing concentrations of acerola. Under the storage conditions used, no synergistic effect that allow to control of ratio among fruit pulps that better preserving the powder nutritional properties.

In this study, the influence of oil phase’s solidification extent on the stability of the microcapsules was explored, in which various content of stearic acid (SA) was incorporated into the oil phase. The results showed that moderate solidification of the oil phase (0.8–1.5 % SA in the oil phase) in precursor emulsions had no significant impact on droplet size, and the resulting microcapsules maintained discrete spherical morphology with lower surface oil content and higher bulk density. Reconstituted microcapsules with SA < 2.0 % exhibited homogeneous dispersions. During accelerated storage at 60 °C for 60 days, microcapsules with moderately solidified oil phases (0.8–1.5 % SA) exhibited the lowest surface oil content increase, color change and peroxide value, indicating superior oxidative and physical stability. Excessive solidification (SA > 2.0 %) yielded counterproductive effects owing to microcapsule disruption from over-crystallization. This research provides important insights for the development and commercial application of oleogel-based microcapsule technology.

Microbial contamination of food causes significant economic losses. This study investigates the effectiveness of Intense Pulsed Light (IPL) in eliminating common Gram-negative bacteria in planktonic and biofilm forms on liquid and solid foods under various environmental conditions. Three models were tested: planktonic cells, early-stage biofilms, and mature biofilms. IPL treatments were applied at three capacitance intensities (650 μF, 470 μF, and 220 μF) with varying irradiation cycles. Results showed IPL achieved over 99.9 % sterilization efficacy for planktonic bacteria, while 2-day biofilms exhibited greater resistance than 8-h biofilms. Temperature (4 °C and 25 °C) did not significantly affect IPL efficacy. IPL effectively inactivated four Gram-negative bacterial strains, though sterilization efficacy varied by strain and growth stage. This study demonstrates that IPL is a promising, non-thermal method for microbial control and food preservation, offering a novel approach to enhance food quality and extend shelf life.