Effects of processing techniques on drying characteristics, physicochemical properties and functional compounds of green and red chilli (Capsicum annum L.) powder

Red pepper waste-derived carbon dots incorporated sodium alginate/gelatin composite films for bioactive fruit preservation

The design of cost-efficient and eco-friendly packaging films with multifunctional features such as antimicrobial, antioxidant, and UV protection is important in food industry. Red pepper waste-derived carbon dots (RP-CDs) have been used as reinforcement and active components in the fabrication of advanced packaging materials. The synthesized spherical RP-CDs with an average diameter of 2.5 nm were rich in active functional groups such as -NH2, -OH, -C=O, CO, and C-O-C. Casting method was used to load 1, 2, and 3 wt% of RP-CDs into sodium alginate/gelatin (SA/Gel) polymer matrix. SEM images and FT-IR and XPS analyses confirmed the strong compatibility and potential hydrogen bonding between RP-CDs and the matrix. This interaction improved the mechanical strength and moisture resistance of the composite films. With the addition of 3 wt% RP-CDs, the UV-A barrier, ABTS radical scavenging, and L. monocytogenes bactericidal properties of the composite film increased by 92.5, 100, and 99.9 %, respectively. Fruit preservation results revealed that the prepared SA/Gel/RP-CD3% composite film maintained the freshness of packed grapes and extended their storage life to 24 days. The development of active packaging films with biowaste-derived functional fillers (CDs) offers the dual benefit of extending the shelf life and contributing to food waste management.

The Multifaceted Chemistry of Chili Peppers: A Biodiversity Treasure for Nutrition and Biomedicine

Due to its biodiversity, traditional medicine has been recognized worldwide for centuries and continues to affect the development of complementary and alternative therapies. A wide variety of spices, herbs, and trees are known for their curative effects. Chili pepper (Ch-p), a spice-utilizing fruit, is rich in natural medicinally bioactive compounds, such as flavonoids, capsaicinoids, and many other phytochemicals and phytonutrients. Operating in synergy and consortium, these compounds demonstrate their functionality, in comparison to lonely treatment, as active agents in handling many disorders. These may include abnormal coagulation, oxidative stress, obesity, diabetes, inflammation, cancer, and microbe-inducing diseases. Recently, capsaicinoids, particularly capsaicin, have been shown to manage the symptoms of significant viral diseases, including COVID-19. Capsaicin also has the potential to be an effective anesthetic agent and enables Ch-p to be expandedly employed as a topical preparation in relieving pain as well. The phytochemicals of Ch-p are not only beneficial and inexpensive phyto-alternatives in disease management, but they can also be used as scaffolds for the production of novel medicines. The study also substantiates the role of the TRPV1 receptor in the mitigation of chronic diseases in conjunction with capsaicin. Nevertheless, the consumption of Ch-p is the subject of limited medicinal research, necessitating the confirmation of the results from animal studies. The nutritional and biomedical prospection of Ch-p-derived products has been addressed in an accessible format in this artifact, with the potential to precisely enhance and enrich our pharmaceutical industries in the pursuit of human well-being.

Varietal influence on bioactive compounds and antioxidant activity in chilies during development stages

Numerous cultivars of chili are grown in Bangladesh for their nutritional and sensory attributes, serving as both spices and food items. Among many, indigenous chili cultivars in Bangladesh include Sada Akshi, Kajini, Dhani, and Naga are the important ones. The functional qualities of chili peppers are attributed to the plentiful presence of bioactive substances. Consequently, this study aimed to determine the variations in bioactive compounds, antioxidant activities, and hotness among the pre-mature, mature, pre-ripening, and ripening stages of four distinct chili cultivars. Four different cultivars of chilis at four different maturity stages were collected and analyzed for their antioxidant and bioactive profiles. The findings of the research revealed that all chili varieties exhibited a notable range of vitamin C concentration, ranging from 1.67 to 8.45 mg/g FW during the maturity stages. The values of TPC, TFC, total carotenoids, and chlorophyll a and b ranged from 16.68 to 46.76 mg GAE/g, 2.80-8.53 mg QE/g, 4.31-85.79 μg/g DW, 2.83-15.54 and 0.74-5.66 μg/g DW on a dry weight basis, respectively. The antioxidant activity was assessed using the FRAP and the DPPH scavenging assay and the values ranged from 142.62 to 311.03 mM Fe (II) Equivalent/100g DW and 216.36-329.52 μM Trolox Equivalent/g DW, respectively. The content of vitamin C, TPC, total carotenoids, and chlorophyll b was increased with the stages of development. The hotness of chili also increased with the development stages. However, the antioxidant activity fluctuated during the development stages of chili. Furthermore, the study incorporated the evaluation of physical parameters, such as height, weight, and color attributes concerning chilies. The Naga variety of chili demonstrated the highest level of efficacy when compared to other varieties. The nutritional and physicochemical information of the different cultivars of chili in this study might be useful to the breeders, spice processors, and consumers for desired size, taste, and hotness with health-promoting bioactive compounds, eventually for determining the harvest time.

Influence of the Drying Process on the Volatile Profile of Different Capsicum Species

Chili is a globally significant spice used fresh or dried for culinary, condiment, and medicinal purposes. Growing concerns about food safety have increased the demand for high-quality products and non-invasive tools for quality control like origin tracing and safety assurance. Volatile analysis offers a rapid, comprehensive, and safe method for characterizing various food products. Thus, this study aims to assess the impact of the drying process on the aromatic composition of various Capsicum species and to identify key compounds driving the aromatic complexity of each genetic makeup. To accomplish these objectives, the aroma was examined in fruits collected from 19 different pepper accessions (Capsicum sp.) belonging to four species: one ancestral (C. chacoense) and three domesticated pepper species (C. annuum, C. baccatum and C. chinense). Fresh and dried samples were analyzed using a headspace PTR-TOF-MS platform. Our findings reveal significant changes in the composition and concentration of volatile organic compounds (VOCs) from fresh to dried Capsicum. Notably, chili peppers of the species C. chinense consistently exhibited higher emission intensity and a more complex aroma compared to other species (both fresh and dried). Overall, the data clearly demonstrate that the drying process generally leads to a reduction in the intensity and complexity of the aromatic compounds emitted. Specifically, fresh peppers showed higher volatile organic compounds content compared to dried ones, except for the two sweet peppers studied, which exhibited the opposite behavior. Our analysis underscores the variability in the effect of drying on volatile compound composition among different pepper species and even among different cultivars, highlighting key compounds that could facilitate species classification in dried powder. This research serves as a preliminary guide for promoting the utilization of various pepper species and cultivars as powder, enhancing product valorization.

Post-harvest profile, processing and value addition of dried red chillies (Capsicum annum L.)

Chilli has dominated and retained an important place amongst the spices worldwide. They are dried ripe fruits intuitively consumed as a spice, condiment, culinary, and medicinal purposes. The global consumption pattern is intriguing because of the inherent pungency, aroma, taste, spicy flavour, and therapeutic properties. Predominantly, the colour and pungency decide the quality features and are actively responsible for organized marketing and trade of the dried chillies. India is one of the leading producers and exporters of chilli. The chemical composition of the chillies varies substantially with agro-climatic zones and post-harvest management strategies. The quantum of post-harvest loss of 25-35% hampers the farmer's income and affects the wholesale/retail marketing. This review paper is intended to provide a deep insight into the advancements in various post-harvest unit operations of dried red chillies. A detailed overview of post-harvest operations (drying, grading, destalking, packaging, storage) and processing techniques for value-added products (chilli powder, dried flakes, seeds, oleoresin) is discussed in this paper. The presented information will help the researchers and the industry personnel engaged in the post-harvest processing and value addition of dried red chillies.

Graphical abstract

Comparative evaluation of ethylene oxide, electron beam and gamma irradiation treatments on commonly cultivated red chilli cultivars (Kunri and Hybrid) of Sindh, Pakistan

Chillies are considered a universal ingredient for imparting flavor and pungency to foods. Pakistan stood in the top twenty countries worldwide by producing 82 thousand Tons of chillies during 2022-23. Chilli fungal contamination and aflatoxin production during drying is a common problem during post-harvest process. Gasses treatment and Ionizing radiations are efficient methods for reducing toxigenic and pathogenic microbial growth in food items. The current study was designed to compare the effects of ethylene oxide (ETO), gamma (GB) & electron beam (EB) treatments on two red chilli local cultivars (Kunri and Hybrid) of Pakistan. After treatment, the chilli samples were analyzed for aflatoxins, physicochemical, quality & safety attributes. All results were subjected to Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), dendrogram and ANOVA to check the correlations, grouping and level of significance within the varieties and treatments. The results showed that moisture and water activity mainly designated PC-2 directions and are slightly positively correlated. Conversely, both fat and proteins have a negative correlation with moisture, ash and water activity. Besides, carotenoids and ABTS assay mainly designated PC-2 directions and are slightly positively correlated. Color, flavonoids and TPC also possess positive correlations among them. ETO depicts effectiveness in the reduction of E. coli but is not effective in saving antioxidant potential such as total flavonoids. Similarly, gamma irradiations showed strong reduction trends in fungal and pathogenic count, however same trend was observed in ascorbic acid too. Besides, the electron beam with dosage levels of 12 and 15 kGy has shown effectiveness against Aspergillus spp., aflatoxins and pathogenic microbial load in addition to saving antioxidant potential (phenolics and flavonoids), physicochemical parameters and color values compared to other applied methods especially in Kunri variety. It was evident from the research that varietal combination in addition to applied treatment must be specially considered while designing a treatment for chillies.

Development of an HPLC-PDA Method for the Determination of Capsanthin, Zeaxanthin, Lutein, β-Cryptoxanthin and β-Carotene Simultaneously in Chili Peppers and Products

For the better standardization and widespread application of the determination method of carotenoids in both chili peppers and their products, this work reports for the first time the simultaneous determination of five main carotenoids, including capsanthin, zeaxanthin, lutein, β-cryptoxanthin and β-carotene in chili peppers and their products, with optimized extraction and the high-performance liquid chromatography (HPLC) method. All parameters in the methodological evaluation were found to be in good stability, recovery and accuracy compliance with the reference values; the R coefficients for the calibration curves were more than 0.998; and the LODs and LOQs varied from 0.020 to 0.063 and from 0.067 to 0.209 mg/L, respectively. The characterization of five carotenoids in chili peppers and their products passed all the required validation criteria. The method was applied in the determination of carotenoids in nine fresh chili peppers and seven chili pepper products.

Functional dairy products as a source of bioactive peptides and probiotics: current trends and future prospectives

Milk is an incredibly healthy food world-wide. However, the 'lactase deficient' individuals cannot digest milk's carbohydrate lactose. A large part of the world population is depriving of highly beneficial milk proteins like casein, lactoalbumin, lactoglobulin, etc. due to lactose intolerance. Production of functional foods and bioactive peptides from milk with natural antioxidants and the addition of probiotics could be the best alternative to extend the use of milk functionalities. Among different probiotics, the lactic acid bacteria (LAB) like Lactobacillus delbrueckii sub sp. bulgaricus, Streptococcus thermophilus and some species of Bifidobacteria and their metabolites (paraprobiotics and postbiotics) have been given more preference to add in milk-derived functional foods. These species are generally considered as heat-tolerant, highly proteolytic, and peptidolytic towards milk proteins and they liberate smaller molecules of bioactive peptides during fermentation and other processes that stimulate the enzyme lactase to help people in digestion of milk carbohydrate lactose. Moreover, the incorporation of natural antioxidants in yoghurt and other dairy products prevents the rancidity of milk fat. The level of bioactive peptides produced in milk-derived functional foods can be determined by capillary zone electrophoresis, mass spectrometry, fractionation, and other modern assessment techniques. Commercial production of functional probiotic products with bioactive peptides could significantly contribute to reduce milk spoilage, enhance health benefits as well as the growth of the agro-processing industry.

Green alternative methods for pretreatment of whole jujube before the drying process

BACKGROUND

Jujube contains a waxy cuticle that acts as a barrier against fungal pathogens, prevents nutrition damage and leakage due to mechanical damage, and maintains water content. Chemical treatment before drying is the most commonly used method for whole jujube. Although chemical pretreatment can effectively enhance drying kinetics, it can lead to the loss of soluble nutrients and cause food safety issues due to chemical residues. Therefore, this study aimed to explore the effect of various pretreatments (cold plasma, cold plasma activated water, ultrasonics, thermosonication, and blanching) on the drying process and quality properties of whole jujube so as to find effective green alternatives to chemical pretreatment.

RESULTS

The application of chemical, cold plasma, and thermosonication significantly altered the surface morphology of jujube by etching larger cracks and holes, which can facilitate the transfer of moisture, thereby improving the drying rate and the effective diffusivity. Chemical, cold plasma, and thermosonication pretreatment reduced drying time by 18%, 12%, and 7% respectively, thereby increasing the content of total phenolics by 13%, 12%, and 6% respectively, and enhancing antioxidant capacity (ferric reducing antioxidant power) by 13%, 11%, and 3% respectively. In addition, chemical and cold plasma pretreatment reduced the generation of 5-hydroxymethylfurfural by 25% and 15% respectively.

CONCLUSION

Cold plasma is a promising green alternative method to chemical pretreatment for drying processes of whole jujube. © 2021 Society of Chemical Industry.

The efficacy of washing strategies in the elimination of fungicide residues and the alterations on the quality of bell peppers

Food safety problems caused by pesticide residues in vegetables have become a top issue to raise public concern. In this study, bell peppers were grown in an experimental field and sprayed with two systemic (azoxystrobin and difenoconazole) and one contact (chlorothalonil) fungicides. Ozone (ozonated water and water continuously bubble with ozone) or conventional domestic (washing with distilled water, detergent, acetic acid, sodium bicarbonate, and sodium hypochlorite solutions) procedures were investigated to identify the most effective way to remove fungicide residues in bell peppers. The residues in the fruits and the washing solutions were determined by solid-liquid extraction with a low-temperature partition (SLE/LTP) and liquid-liquid extraction with a low-temperature partition (LLE/LTP), respectively, and analyzed by gas chromatography. Water continuously bubbled with ozone a concentration of 3 mg L^-1 was the most efficient treatment with removal of fungicides residues ranging from 67% to 87%. However, similar treatment at a lower concentration (1 mg L^-1) did not only efficiently removed fungicide residues (between 53% and 75%) but also preserving the quality of the fruit along a storage time of 13 days. Among the conventional solutions, sodium bicarbonate at 5% showed good efficiency removing between 60% and 81% of the fungicide residues from bell peppers, affecting the color quality of the fruit. Overall, the most affected physicochemical parameters in bell peppers after the treatments were weight loss, color, and vitamin C content.