Adsorption-desorption of anthocyanins from jambolan (Syzygium cumini) fruit in laponite® platelets: Kinetic models, physicochemical characterization, and functional properties of biohybrids

Intelligent labels manufactured by thermo-compression using starch and natural biohybrid based

This work aims to develop intelligent labels based on cassava starch and biohybrid pigments by thermo-compression. The biohybrid pigment (BH) was developed by the adsorption of anthocyanins (ACNs) extracted from the jambolan fruit (Syzygium cumini L.) into montmorillonite (Mt) in order to improve its stability. The effect of the addition of biohybrid on the physicochemical properties of the thermo-pressed starch labels was evaluated. ACNs from jambolan extract show a visible pH-dependent color-changing ability at pH 1 - 12, and the adsorption did not modify the color property. The intelligent labels presented a homogeneous surface, and the BH was well dispersed in the starch matrix. The presence of BH increased the solubility in the water of starch labels. Chemical structure characterization revealed that the BH interacted with starch matrices through hydrogen bonds. Furthermore, the thermal stability of starch labels increased with the presence of BH. Hence, the purple color of intelligent labels was preserved at high temperatures. Finally, labels containing BH show visible changes from purple to a blue color when exposed to ammonia vapor, which simulates the degradation of meat products. Thus, the label content jambolan pigments will be used to control meat deterioration.

Olfactory and gustatory disorders caused by COVID-19: How to regain the pleasure of eating?

Background

Recently, anosmia and ageusia (and their variations) have been reported as frequent symptoms of COVID-19. Olfactory and gustatory stimuli are essential in the perception and pleasure of eating. Disorders in sensory perception may influence appetite and the intake of necessary nutrients when recovering from COVID-19. In this short commentary, taste and smell disorders were reported and correlated for the first time with food science.

Scope and approach

The objective of this short commentary is to report that taste and smell disorders resulted from COVID-19 may impact eating pleasure and nutrition. It also points out important technologies and trends that can be considered and improved in future studies.

Key findings and conclusions

Firmer food textures can stimulate the trigeminal nerve, and more vibrant colors are able to increase the modulation of brain metabolism, stimulating pleasure. Allied to this, encapsulation technology enables the production of new food formulations, producing agonist and antagonist agents to trigger or block specific sensations. Therefore, opportunities and innovations in the food industry are wide and multidisciplinary discussions are needed.

Halloysite and Laponite Hybrid Pigments Synthesis with Copper Chlorophyll

Sustainable and green materials have been studied in dye and pigment productions to reduce their environment impacts from being produced and applied. Although natural dyes are an excellent choice to move from agrowaste, some improvements must be made before they are applied given their poor fastness. One way of improving natural dye properties is their adsorption into nanoclay structures to give hybrid pigments. This work used tubular halloysite and laminar laponite to adsorb and stabilize natural copper chlorophyll. With a statistical design of experiments, we observed interactions between synthesis factors, such as pH, ionic strength, and surfactant or silane modification. Cool hybrid pigments with high TSR (%) values and a wide color range were obtained by using dispersions with only distilled water at room temperature. Successful chlorophyll adsorption on both nanoclay surfaces took place by XRD and DTA analyses. The maximum natural dye absorption for both nanoclay types took place under acid conditions, pH 3–4, and in the presence of mordant. The TSR (%) improved by the silane pH interaction, and halloysite hybrid pigments obtained higher TSR values than the laponite ones. Finally, a wide chromatic green color range was obtained with the surfactant modification in both nanoclays, and the color fastening was also improved in the hybrid pigments application. The samples generated with 10% of hybrid pigments from both nanoclays and an Epoxy bioresin, show higher colorfastness than the sample with the natural chlorophyll, due to the nanoclays–dye interaction and protection.

Anthocyanin Hybrid Nanopigments from Pomegranate Waste: Colour, Thermomechanical Stability and Environmental Impact of Polyester-Based Bionanocomposites

In the present work, anthocyanin (ACN) hybrid nanopigments were synthetized by using a natural pomegranate dye (PD) and calcined hydrotalcite (HT) and montmorillonite (MMT) nanoclays. A wide colour gamut was obtained with MMT-based nanopigments ranging from reddish to bluish hues caused by structural transformations of ACNs at different pH values. However, a buffer effect was observed with HT obtaining samples a similar final colour regardless of the synthesis conditions. Nanopigments added with a biomordant extracted from pomegranate peels showed a different colour compared to the incorporation of a commercial mordant due to the intrinsic colouring properties of the pomegranate bioadditive. The developed nanopigments were incorporated at 7 wt% loading to produce novel polyester-based bionanocomposites which were characterized in terms of thermal, mechanical and colour properties. The encapsulation of PD into the nanoclays improved its thermal stability, in particular for MMT-based nanopigments. The pH changes observed during the nanofillers synthesis affected the final colour of the MMT-based nanocomposites, inducing a general increase in ∆E* and a decrease in gloss values. Slight improvements were obtained in terms of elastic modulus for MMT-based polymer samples confirming the applicability of the developed bionanocomposites as colouring and reinforcement materials. A very similar environmental profile was obtained for MMT and HT-based nanofillers showing MMT-based nanopigments a slightly better general behaviour. The results of the LCA study evidenced the suitability of the processes used in this work to the circular bioeconomy approach through sustainable food waste management and the production of bioplastics using waste substrates.

Behaviour desorption study of the essential oil of Cedrus atlantica in a porous clay versus insecticidal activity against Sitophilus granarius: explanation of the phenomenon by statistical studies

Substances of natural origin and more particularly essential oils currently represent an alternative solution in the fight for the protection of stored foodstuffs. The way to use these essential oils and the storage conditions remain the main handicap in dealing with this subject. This article develops the use of porous supports as a medium for the study of the behavior of essential oils with respect to insecticidal activities. The process relates to the fixing and/or grafting of essential oils in porous clay media in a well-defined geometric form included in the storage methods. The study of transfers of the essential oil of Cedrus atlantica in a porous clay medium in the case of desorption was made by analytical and numerical models of diffusion process, to know the behavior of the oil and to determine some physical parameters (diffusivity Dz, activation energy Ea, evaporation rate F and constant of evaporation K) which explain the mechanisms involved and to try to exploit them in parallel with the insecticidal activities against of Sitophilus granarius the main cereal pest by statistical approaches such as: design of experiments and principal component analysis.