Fabrication of multifunctional materials based on chitosan/gelatin incorporating curcumin-clove oil emulsion for meat freshness monitoring and shelf-life extension.

A new multifunctional film with active and intelligent effects was developed by incorporating curcumin-clove oil emulsion into natural materials. The basic properties, functional characteristics, and pH/NH3-sensitivity of films were investigated, and then these films were applied to extend shelf-life and monitor freshness of meat. Curcumin solution and emulsion illustrated significant color variations at different pH values. The incorporation of emulsion improved the UV-vis barrier and water resistance properties of films, which blocked most of UV-light and its water contact angle reached 100.03°. Meanwhile, the films had stronger mechanical strength and higher thermal stability, with elongation at break reaching 79.18 % and the maximum degradation temperature rising to 316 °C. Moreover, emulsion made films have a slow-release effect on clove oil, which not only enhanced the antioxidant property but also significantly improved their antibacterial activity. Additionally, the multifunctional films presented a significant color response to acidic/alkaline environments over a short time interval and could be easily identified by naked eyes. Finally, the films effectively extended the shelf-life of fresh meat by 3 days at 4 °C and visually monitored freshness through color changes in real-time. This knowledge provides insights and ideas for the development of novel food packaging with both active and intelligent functions.

Comparison of citrus pectin and apple pectin in conjugation with soy protein isolate (SPI) under controlled dry-heating conditions.

In this study, we selected two most commonly-available commercial pectin, i.e. citrus pectin and apple pectin as the grafting polysaccharides to prepare soy protein isolate-pectin conjugates. Despite the similar degrees of methoxylation and acetylation for two pectin samples, apple pectin showed much more complex structures compared to citrus pectin, with a 2.20-fold higher molecular weight and large numbers of side chains. The conjugates were prepared under controlled dry-heating conditions and achieved the degree of graft of 25.00% and 21.85% for citrus and apple pectin, respectively. Formation of the conjugates was further confirmed by SDS-PAGE gel electrophoresis and IR spectra. Attributed to the strong steric-hindrance effect of pectin, the fluorescence intensity and surface hydrophobicity of the soy protein isolate were significantly decreased after Maillard reaction. However, both solubility and emulsifying properties of the conjugates were significantly improved. Results indicated that both pectin samples played favorable roles in protein modification.

Effects of an Integrated Neurofeedback System with Dry Electrodes: EEG Acquisition and Cognition Assessment.

Electroencephalogram (EEG) neurofeedback improves cognitive capacity and behaviors by regulating brain activity, which can lead to cognitive enhancement in healthy people and better rehabilitation in patients. The increased use of EEG neurofeedback highlights the urgent need to reduce the discomfort and preparation time and increase the stability and simplicity of the system's operation. Based on brain-computer interface technology and a multithreading design, we describe a neurofeedback system with an integrated design that incorporates wearable, multichannel, dry electrode EEG acquisition equipment and cognitive function assessment. Then, we evaluated the effectiveness of the system in a single-blind control experiment in healthy people, who increased the alpha frequency band power in a neurofeedback protocol. We found that upregulation of the alpha power density improved working memory following short-term training (only five training sessions in a week), while the attention network regulation may be related to other frequency band activities, such as theta and beta. Our integrated system will be an effective neurofeedback training and cognitive function assessment system for personal and clinical use.

Age-related oscillatory theta modulation of multisensory integration in frontocentral regions.

This study used electroencephalogram measurements to investigate the effects of aging on oscillatory theta modulation during an audiovisual discrimination task. By a wavelet-based time-frequency analysis, age-related theta oscillation response differences were observed within a relatively restricted time range (0-500 ms) over frontal-central regions. Older adults showed stronger theta spectral power during visual and audiovisual stimuli in the left frontal regions; however, young adults showed stronger theta spectral power during auditory and audiovisual stimuli in the central regions. These findings suggest that multisensory oscillatory theta responses differ according to age, which further proves that the left frontal regions play an important role in audiovisual integration.

Interactions between multisensory inputs with voluntary spatial attention: an fMRI study.

Cross-modal attention and multisensory integration are very essential for us to perceive the world. The most intuitive feelings about the environment around us are based on what we see and what we hear. Therefore, it is important to understand the interactions between visual inputs and auditory inputs. Previous studies have shown that multisensory integration can be modulated by attention. However, how top-down attention is controlled or allocated across the sensory modalities remains unclear. In this study, we measured the cortical areas activated by the cue-target spatial attention paradigm in both visual and auditory fields using functional MRI. The reaction times of the behavioral results indicated that interactions between the two types of stimuli exist. The imaging results indicated that interactions between multisensory inputs can lead to enhancement or depression of the cortical response with top-down spatial attention. Moreover, the activation of the middle temporal gyrus and insula in tasks with irrelevant stimuli appears to indicate that multisensory integration proceeds automatically.