Edible coating using carbon quantum dots for fresh produce preservation: A review of safety perspectives.

Fresh produce deteriorates and spoils after harvest due to its perishable nature. Deterioration in quality over time has become a major problem for the food industry, placing an undue burden on the economy and agriculture. Food scientists have developed various methods and technologies to prevent spoilage of fruits and vegetables during storage and logistics. Utilizing carbon quantum dots (CQDs) in the form of active packaging and coatings has been a popular strategy recently. CQDs have recently attracted attention as sustainable and functional nanomaterials. CQDs are popular among food scientists due to their easy and economical synthesis, sustainability, non-toxicity, biocompatibility, edibility, UV protection, and antibacterial and antioxidant activities. Although many studies have been conducted and reviewed on the utilization of CQDs in the manufacture of flexible active packaging materials, relatively few studies have investigated the use of CQDs in edible coating formulations for fresh produce. The main reasons for this are concerns about the potential toxicity and edibility of CQDs if they are coated directly on fresh produce. Therefore, this review aims to address these issues by investigating the dose-dependent non-toxicity and biocompatibility of sustainable CQDs along with other important properties from a food packaging perspective. Additionally, this review focuses on the studies performed so far on the direct coating of CQD-based formulations on fresh and fresh-cut fruits and vegetables and discusses the important impact of CQDs on the quality of coated agricultural products. This review is intended to provide food packaging researchers with confidence and prospects for utilizing sustainable CQDs in direct coating formulations for food.

Investigation of formation of AGEs precursors, hydroxymethylfurfural and malondialdehyde in oleogel added cakes using an in vitro simulated gastrointestinal digestive system.

The baking process has the potential to generate health-risk compounds, including products from lipid oxidation and Maillard reaction. Pre- and post-digestion levels of hydroxymethylfurfural (HMF), malondialdehyde (MDA), glyoxal (GO), and methylglyoxal (MGO) were studied in cakes formulated with hazelnut and sunflower oil, along with their oleogels as margarine substitutes. The concentration of HMF in oil and oleogel-formulated cakes increased after digestion compared to cakes formulated with margarine. The MDA values were between 82 and 120 µg/100 g in oil and oleogel formulated cakes before digestion and a decrease was observed after digestion. The substitution of margarine with oil and oleogels resulted in the production of high amounts of GO and MGO in cakes. However, the highest bioaccessibility as 318.2% was found in cakes formulated by margarine for GO. Oleogels may not pose a potential health benefit compared to margarines due to the formation of HMF, MDA, GO, and MGO.

Improving Cleaning Efficiency through the Measurement of Food Fouling Adhesive Strength.

This study aims to investigate the impacts of factors, including textural properties, surface roughness, and contact angle, on the cleaning performance of food soils and develop a preliminary mathematical model to predict the cleaning score, depending on the soil-surface properties. The force required to remove soil from the surface was determined by a texture analyzer equipped with a newly designed probe. Potato puree and egg yolk soils showed high adhesive forces compared to other deposits. Margarine required the lowest force to detach from the surfaces. A soil-surface characteristic number (SSCN) was constructed from the results of contact angle, roughness, and textural analysis to predict the cleaning score depending on the soil-surface properties. The experimental work presented indicates that a higher SSCN was associated with lower cleaning scores for soil-surface combinations. Furthermore, a predictive model was developed to define the relationship between cleaning scores and SSCN. The applicability of the model was validated by measuring the cleaning performance of caramel and pudding soils on glass, porcelain, and stainless-steel household surfaces by using an automatic method. Therefore, it can be concluded that the SSCN approach can be improved in further studies to predict cleaning scores of soil-surface combinations in the experimental rig or automatic dishwasher.

Characterization of zein assemblies by ultra-small-angle X-ray scattering.

Zein, a major corn protein, has an amphiphilic molecule capable of self-assembling into distinctly different structures, i.e., rods, sheets, and spheres. In this work, ultra-small-angle X-ray scattering (USAXS) was applied to investigate the formation of self-assembled zein structures in binary solvent systems of ethanol and water. The study included observing structural changes due to aging. Three distinctive regions, each corresponding to different co-existing structures having a hierarchical organization, were observed in zein-solvent systems. Rod shaped (Rg = 1.5-2.5 nm, P = 1) primary structural units were identified, believed to be molecular zein. Two-dimensional sheet-like structures (Rg = 80-200 nm, 2 < P < 3) were observed, believed to be formed by primary units first assembled into one-dimensional fibers and then into 2D sheet structures. Also, large three-dimensional spherical aggregates were observed (Rg > 1000 nm, P = 4), believed to have assembled from two-dimensional sheet structures. Aging did not change the size or the shape of the primary units, but USAXS detected changes in Rg and P values of the intermediate structures, pointing to a further level of self-assembly where proteins develop a more regular and organized structure. The viscoelastic moduli (G' and G''), the consistency index (K) and the flow behavior index (n), were also measured to investigate the effect of zein structural development by self-assembly on rheological behavior. Samples became more solid-like with aging. Raman spectra suggested that zein underwent secondary structure transformations from α-helix to ß-sheets, which influenced the size and morphology of molecular assemblies and ultimately the rheological properties of zein solutions.