Biological Control of Patulin by Antagonistic Yeast: A case study and possible model.

The occurrence of patulin in fresh apples and apple products is a great burden from health, safety and economic perspectives. Attempts to prevent patulin accumulation in fruits might lead to the excessive use of fungicides. Therefore, guaranteeing the safety of apple foods is crucial for the international apple industry. Recently, literature revealed that application of antagonistic yeasts and other BCAs have been able to disrupt the process of fungal infection and patulin production in apples. Although, over the years the effect of interaction between BCAs and fungi on patulin production has been reported, the exact mechanism(s) of their action remain unclear. Here, the review focused on toxicology and occurrence of PAT; research advances made over the past few years on the interaction between antagonistic yeast, fruits and patulin-producing fungi; the prevalence of patulin in apple fruits and products and the implications of synthetic-fungicide applications. In addition, attention was focused on the mechanism(s) and the enhancement of the biocontrol efficacy of antagonistic for patulin control.

Fabrication of biopolymer stabilized microcapsules for enhancing physicochemical stability, antioxidant and antimicrobial properties of cinnamon essential oil.

The current study entails the encapsulation validity to enclose naturally occurring food preservatives, such as cinnamon essential oil (CM), within various wall materials. This approach has demonstrated enhanced encapsulated compounds' stability, efficiency, and bioactivity. The base carrier system consisted of a solid lipid (Berry wax, RW) individually blended with whey protein (WYN), maltodextrin (MDN), and gum Arabic (GMC) as wall materials. The resulting formulations were freeze-dried: WYN/RW/CM, MDN/RW/CM, and GMC/RW/CM. The study comprehensively analyzed encapsulation efficiency, morphology, crystallinity, thermal, and physiochemical properties. When RW was combined with WYN, MDN, and GMC, the microcapsule WYN/RW/CM showed the highest efficiency at 93.4 %, while the GMC/RW/CM exhibited the highest relative crystallinity at 46.54 %. Furthermore, the investigation assessed storage stability, release of bioactive compounds, and oxidative stability during storage at 4 °C/ 25 % RH ± 5 % and 25 °C/40 % RH ± 5 % for 55 days, revealing optimal stability in the WYN/RW/CM microcapsule. Additionally, the antimicrobial activity was assessed at various concentrations of microcapsules, revealing their inhibitory effect against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) bacteria. The WYN/RW/CM microcapsule exhibited the highest inhibition activity in both strains, reaching 40 mm. This study demonstrates that combining WYN with RW as a wall material has greater efficiency in encapsulation and potential uses in various industrial sectors.

Smart films of carbohydrate-based/sunflower wax/purple Chinese cabbage anthocyanins: A biomarker of chicken freshness.

Innovative pH-colorimetric sensor film was fabricated from agar and methylcellulose matrix (AM) with various concentrations of sunflower wax (SFW) (6%, 9%, 12%, and 15% w/w) combined with purple Chinese cabbage (CPC) anthocyanins for tracking chicken breast freshness. A bio-composition film AM/CPC with (hydrophobic) SFW exhibited significant color variations in acidic pH level of (2-6) and a slight shift in alkaline pH levels ranging from (7-12), as well as marked color change due to ammonia vapor. Microstructure analyses revealed that SFW was fixed effectively into the AM-CPC matrices. The incorporation of varying SFW concentrations enhanced the mechanical, thermal, antioxidant activity, reduced anthocyanin release and physical properties (mainly water vapor permeability), with the best performance at AM/CPC/9% SFW. Interestingly, SFW films demonstrated perfect defense opposing UV-vis and visible light. Finally, it was proved that the efficiency of the pH-colorimetric film as an indicator for evaluating the freshness of chicken breast.

Effect of gum arabic edible coating incorporated with African baobab pulp extract on postharvest quality of cold stored blueberries.

The marketability of blueberries over long distances has been limited because of their highly perishability. To prolong the postharvest shelf life and conserve quality properties of blueberry, various alternatives have been evaluated. We studied the influence of gum arabic (GA) alone or GA enhanced with African baobab (AB) fruit extract on blueberry during cold storage (4 °C) for 21 days. Physico-chemical properties (e.g. pH, color, firmness, and weight loss), microbial decay, antioxidant properties, polyphenol oxidase (PPO) and peroxidase (POD) activity were investigated. The fruit treated with GA combined AB indicated a significant delay in microbial decay, firmness loss, weight loss, and color change. The treatments on blueberries resulted in better preservation of total phenols and total anthocyanins delayed the increase in total soluble solids as compared to the control. The coatings lowered the activities of PPO and POD enzymes and delayed microbial decay in coated blueberry during 21 days of storage.

Recent developments in gum edible coating applications for fruits and vegetables preservation: A review.

Gums are a class of naturally occurring polysaccharides/carbohydrate polymers derived from renewable sources, which have the capacity to hydrate in water either by forming a gel or stabilizing emulsion systems. Among the substitutes recently considered to replace the application of petroleum-derived polymers against postharvest diseases and shelf life extension, gums and their derivatives have been considered as promising biocontrol products. Polysaccharide gum coatings provide a semipermeable barrier on the surface of produce to reduce respiration rate, weight loss and maintain the nutritional value. Gums have been used as excellent vehicles for active substances, also controlling the speed of diffusion of these, and improving the control of the maturation of fruit and vegetable. Additionally, plant extracts, essential oils, phenolic compounds, and vitamins can be incorporated into polysaccharides edible coatings in order to improve their mechanical barrier, antioxidant and antimicrobial properties. Gums have many advantages over the synthetic polymers, because they have been approved as GRAS by FAO, and their use is safe for the consumer and eco-friendly. This review aims to highlight the most relevant and current information in the use of polysaccharides in postharvest shelf life extension and preservation of overall quality of fruits and vegetables.

Effects of ultrasound and ultrasound assisted alkaline pretreatments on the enzymolysis and structural characteristics of rice protein.

The objectives of this study were to investigate the effects of multi-frequency energy-gathered ultrasound (MFEGU) and MFEGU assisted alkaline pretreatments on the enzymolysis and the mechanism of two pretreatments accelerating the rice protein (RP) proteolysis process. The results showed that MFEGU and MFEGU assisted alkaline pretreatments improved significantly (P<0.05) the degree of hydrolysis (DH) and the protein elution amount of RP. Furthermore under the same DH conditions, ultrasound and ultrasound assisted alkaline pretreatments were more save the enzymolysis time than the unpretreatment. The changes in UV-vis spectra, fluorescence emission spectra indicated unfolding and destruction of RP by MFEGU and MFEGU assisted alkaline pretreatments. The circular dichroism analysis showed that both pretreatments decreased α-helix but increased ß-sheet and random coil of RP. Amino acid composition revealed that MFEGU and MFEGU assisted alkaline pretreatments could increase the protein elution amount and the ratio of hydrophobic amino acids. Atomic force microscopy (AFM) indicated that both pretreatments destroyed the microstructures and reduced the particle size of RP. Therefore, MFEGU and MFEGU assisted alkaline pretreatments are beneficial to improving the degree of hydrolysis due to its sonochemistry effect on the molecular conformation as well as on the microstructure of protein.