Involvement of iturin and surfactin in inhibition of a post-harvest fungal pathogen on green bell pepper

Storing `Maor' green bell peppers (Capsicum annuum L.) for 3 weeks at 2C resulted in the development of chilling injury (CI) evidenced as surface pitting. Fruit held at 8C did not develop any CI symptoms, but, after 3 weeks of storage, the fruit began to change color from green to red. PAM fluorometry was used to measure changes in photosynthetic competency in whole green bell peppers. Three photosynthetic characteristics could be measured by this method: quantum yield (Fm/Fe), photochemical quenching (Qp), and nonphotochemical quenching (Qnp). Fm/Fo decreased 90% during the first week of storage at 2C and remained low thereafter, while Qnp decreased after 2 weeks at 2C, just before the peppers began to develop CL Qp was similar at both storage temperatures. Potassium leakage as a CI measurement also increased in excised pepper discs after 2 weeks at 2C. The results indicate that PAM fluorometry can measure CI nondestructively before tissue damage is visible in green peppers.

Green peppers are massively produced all over the world; however, substantial quantities of peppers are wasted. Functional polysaccharides can be produced from pepper waste. A conventional acid extraction method was used to obtain pectin-like materials from green bell pepper (GBP). A 23 experimental design (two-level factorials with three factors: temperature, pH, and time) was used to study the relationship between the extraction conditions and the measured physicochemical properties. The extracted polysaccharides were further analysed regarding their physicochemical and functional properties. The yields were in the range of (11.6–20.7%) and the highest yield value was extracted at pH 1. The polysaccharides were classified as “pectin-like”, as the galacturonic acid content was lower than 65%. Glucose and galactose were the major neutral sugars, and their relative amounts were dependent on the extraction conditions. The degree of esterification (DE) of the pectin-like extracts was greater than 50% and they were therefore classified as high methoxyl regardless of the extraction conditions. Also, important levels of phenolic materials (32.3–52.9 mg GAE/g) and proteins (1.5–5.4%) were present in the extract and their amounts varied depending on the extraction conditions. The green bell pepper polysaccharides demonstrated antioxidant and emulsifying activities and could also be used adequately to stabilise oil/water emulsion systems. This finding shows that green bell pepper could be used as an alternative source of antioxidants and an emulsifier/stabilising agent, and furthermore, the extraction conditions could be fine-tunned to produce polysaccharides with the desired quality depending on their application.

The main objective of this work is to assess the effect of natural extracts and its characterization for the mitigation of multiple pesticide residues in green bell pepper. In this study, four plant extracts such as Acacia concinna, Albizia amara, Tamarindus indica, and Azadirachta indica have been used to mitigate the six pesticides present in green bell pepper and its phytochemical constituents were analyzed using gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC–MS/MS). In addition to that, the method for the quantification of six pesticide residues in green bell pepper using GC–MS/MS was validated according to SANTE/11312/2021 guidelines. The extracts of Acacia concinna, Albizia amara, Tamarindus indica, and Azadirachta indica were showed effective mitigation for selected pesticides. The phytochemical compounds present in plant extracts were correlated with its effect on the mitigation of multiple pesticide residues. The T. indica showed better pesticide mitigation efficiency when compared to A. indica, A. amara, and A. concinna, respectively. The plant extracts showed higher mitigation efficiency for organophosphorous pesticides than the synthetic pyrethroids. The nutritional and sensorial properties of green bell pepper were highly retained after pesticide decontamination using plant extracts. The results of this work indicated the application of plant extracts for the mitigation of multiple pesticides in green bell pepper by household and commercial processing units. This study addressed the balance between food safety and food quality.Practical ApplicationsPesticide contamination in vegetables is one of the major global food safety issues and it poses potent threat to human health. Pesticide decontamination is always a challenging task due to the unpredictability of types and levels of pesticides and the presences of multiple pesticides in contaminated vegetables. Washing of vegetables with water is the common procedure followed by both household and commercial units. However, washing of vegetables only with water is not enough to reduce the multiple pesticides residues to safe levels. The washing of vegetables with chemical solutions and other thermal and non‐thermal processing could result in toxic byproduct formation based on the types of pesticides present in contaminated sample. Hence, in this study, the plant extracts were characterized for its efficiency on the mitigation of multiple pesticide residues in vegetables has been analyzed by Gas Chromatography—Triple Quadrupole Tandem Mass Spectrometry and the method has been validated according to SANTE/11312/2021 guidelines. The phytochemical compounds of the plant extracts could be correlated with the effective multiple pesticide decontamination efficiency and the plant extracts were found to retain the physicochemical properties of vegetables during washing. The results of this study showed that the selected plant extracts could enhance the food safety without compromising food quality. The results of this study could be useful for the formulation of vegetables cleaning solutions for the effective mitigation of multiple pesticide residues.

The aim of this study was to quantify the amount of Salmonella enterica serovar Typhimurium transferred from volunteers' hands (bare or gloved) to green bell peppers and vice versa; and to assess the effectiveness of hand hygiene techniques. The highest and lowest percentages of bacterial transfer were achieve from green bell peppers to gloved hands (46.56%) and from bare hands to green bell peppers (0.21%), respectively. The highest and lowest Log10 reductions of S. Typhimurium were achieved by the combination of hand washing and alcohol-based gel (4.38 Log10) and iodine solution (2.08 Log10), respectively. This study provides important information concerning the transfer's efficiency of S. Typhimurium from hands to fresh produce and from fresh produce to hands. The study also showed that gloved hands, could be a mean of transfer of S. Typhimurium between green peppers and hands, and the best hand hygiene technique was the combination of hand washing and alcohol-based gel.

Steam cooking significantly improves in vitro bile acid binding of collard greens, kale, mustard greens, broccoli, green bell pepper, and cabbage

Newly designed molecularly imprinted 3-aminophenol-glyoxal-urea resin as hydrophilic solid-phase extraction sorbent for specific simultaneous determination of three plant growth regulators in green bell peppers

The mechanism by which diphenylamine (DPA) controls superficial scald in apples and reduces chilling injury in green bell peppers [Capsicum annuum L. var. annuum (Grossum Group)] has been assumed to be related to its antioxidant activity. In the present study, DPA inhibited the respiratory activity of green bell pepper fruit as well as oxygen uptake by the mitochondria isolated from them. When the alternative oxidase was inhibited with n-propyl gallate or disulfiram during state 4 respiration, DPA did not further inhibit O2 uptake. Treating green bell peppers with DPA before storage did not alter the induction and abundance of the alternative oxidase protein in mitochondria which was maximally induced in peppers stored at 4 °C. Whether added before or after the uncoupler, 2,4-dinitrophenol, DPA negated the enhanced O2 uptake associated with uncoupling of electron transfer in isolated mitochondria. These observations indicate that DPA inhibits the flow of electrons through the cytochrome path, probably somewhere in the cytochrome bc1 complex. Although the secondary amine function of DPA makes it a powerful antioxidant, the effectiveness of DPA in reducing chilling injury in green bell peppers and superficial scald in apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] also may be due, in part, to its inhibition of respiration.

The mechanism by which diphenylamine (DPA) controls superficial scald in apples and reduces chilling injury in green bell peppers [Capsicum annuum L. var. annuum (Grossum Group)] has been assumed to be related to its antioxidant activity. In the present study, DPA inhibited the respiratory activity of green bell pepper fruit as well as oxygen uptake by the mitochondria isolated from them. When the alternative oxidase was inhibited with n-propyl gallate or disulfiram during state 4 respiration, DPA did not further inhibit O2 uptake. Treating green bell peppers with DPA before storage did not alter the induction and abundance of the alternative oxidase protein in mitochondria which was maximally induced in peppers stored at 4 °C. Whether added before or after the uncoupler, 2,4-dinitrophenol, DPA negated the enhanced O2 uptake associated with uncoupling of electron transfer in isolated mitochondria. These observations indicate that DPA inhibits the flow of electrons through the cytochrome path, probably somewhere in the cytochrome bc1 complex. Although the secondary amine function of DPA makes it a powerful antioxidant, the effectiveness of DPA in reducing chilling injury in green bell peppers and superficial scald in apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] also may be due, in part, to its inhibition of respiration.

'Revolution' green bell peppers were harvested, held for 14 to 22 days at 15°C and five relative humidity (RH) levels and evaluated for quality attributes. The objectives of this work were to obtain quality curves at low and recommended RH levels and identify for each RH which quality attributes limit green bell pepper marketability. Results from this study showed that RH had a significant effect on the shelf life and overall quality of green bell peppers. Peppers stored at RHs lower than 90% were less green, softer, more shriveled, and had higher weight loss, lower acidity, lower soluble solids and lower ascorbic acid contents than those stored at higher RH. Overall, changes in the color of the fruit, softening, shriveling, and loss of aroma were the first quality attributes to reach the limit of acceptability and therefore limiting the shelf life of 'Revolution' green bell peppers. At 90 and 95% RH, pepper acceptability was limited primarily by color changes followed by loss of aroma; at 80% acceptability was reduced due to changes in color, shriveling and loss of aroma. Shelf life of peppers stored at 40 and 60% RH was reduced to approximately 6 and 7 days, respectively, due to changes in coloration, softening, severe shriveling and loss of aroma. Maximum shelf life and best quality was obtained when green bell pepper were stored at 90 or 95% RH. The quality curves obtained from quality evaluations for each RH level showed that a single quality attribute cannot be used to express quality loss of green bell pepper stored over a range of humidity levels.

Hydroxypropyl cellulose reduces chilling injury in green bell pepper (Capsisum annuum L.) by regulating the activity and gene expression of enzymes involved in antioxidant and membrane lipid metabolism

This study aimed to (a) analyze the influence of pyrolysis temperature on pistachio shell-based biochar (PSB) properties and (b) assess the PSB effect on green bell pepper (Capsicum annuum L.) growth. Pyrolysis experiments were conducted at different temperatures, determining 450 °C as optimal for soil amendment. The effect of PSB addition at different mass ratios was analyzed considering the physicochemical properties of the mixtures and the agronomic parameters of green bell pepper plants and fruits under greenhouse conditions. Results demonstrated enhancements in soil properties upon biochar incorporation, including a decrease in pH by 1%, a decrease in electrical conductivity (EC) by 4–14%, and increases in cation exchange capacity (CEC) by 4–8%, organic matter (OM) and organic carbon (OC) by 100–200%, and total nitrogen (TN) by 35%, relative to unamended soil. Agronomic variables revealed improvements, particularly during the reproductive and maturity stages, with plants treated with 1% biochar (SB1) exhibiting enhanced growth and chlorophyll content, alongside increased flower and fruit yields. Notably, the 2% biochar treatment (SB2) yielded superior fruit weight and length results, suggesting the potential for biochar to enhance both the quality and quantity of green bell pepper fruits, thereby contributing to sustainable agricultural practices.

The online version contains supplementary material available at 10.1007/s13197-021-05006-7.

Industrial applications of selected <i>JFS</i> articles

Bile acid binding potential of foods and food fractions has been related to lowering the risk of heart disease and that of cancer. Steam cooking has been observed to significantly improve bile acid binding of green/leafy vegetables. It was hypothesized that other cooking methods could further improve the bile acid binding of various vegetables. Sautée cooking resulted in in vitro bile acid binding measured on a dry matter basis relative to cholestyramine of 14% for mustard greens and kale, 9% for broccoli, 8% for collard greens, 6% for cabbage, and 5% for green bell pepper. These results point to the significantly different (P ≤ 0.05) health promoting potential of mustard greens = kale > broccoli > collard greens > cabbage > green bell pepper. Sautéing significantly improved in vitro bile acid binding of mustard greens, kale, broccoli, cabbage and green bell pepper compared with steaming, boiling or raw (uncooked). Collard greens exhibited significantly higher bile acid binding by steaming compared with sautéing, boiling or raw. Data suggest that the cooking method with most heath promoting potential for mustard greens, kale, broccoli, cabbage and green bell pepper should be sautéing. Steaming should be used for collard greens as the cooking method. These green/leafy vegetables, when consumed regularly after sautéing, would promote a healthy lifestyle and have the potential to lower the risk of premature degenerative diseases.

P33 Sensory Perceptions of Cancer Survivors and Their Caregivers of Garden-Harvested and Grocery-Purchased Produce