Edible flowers with the common name “marigold”: their therapeutic values and processing

Background: Edible flowers are defined as innocuous and nontoxic flowers with health benefits when consumed as human diet. So far, hundreds of edible flowers have been identified. Among them, marigold is one of the popular edible flowers which has been used from ancient times. Scope and approach: There are different species of flowers with the common name “marigold”. We have summarized five of them, namely common marigold (Calendula officinalis), marigold (Tagetes erecta), French marigold (Tagetes patula), Mexican mint marigold (Tagetes lucida), and lemon marigold (Tagetes tenuifolia), along with their phytochemical content, physiological effect of these components, and toxicological studies. We have also reviewed the literature dealing with the processing of marigold flowers, such as drying, extraction, and packaging, to find their effect on the bioactive components. Key findings and conclusions: The phytochemical composition of these flowers revealed them to be wonderful natural gifts containing many therapeutic values. Processing of these flowers showed that drying was the most effective method to preserve them; however, novel and hybrid drying technologies using microwave, far infra-red, and ultrasound etc. are still to be studied. Last but not least, it was concluded that marigold flowers are wonderful gifts loaded with natural phytochemicals, if properly processed

Novel intelligent detection of safer water activity by LF-NMR spectra for selected fruits and vegetables during drying

This study investigated the water status provided by LF-NMR spectra measurements for selected fruits (apple and carrot) and vegetables (white cabbage, cauliflower, and radish) during drying with or without sugar or salt treatment. Different shapes of the spectrum for different items and one to four peaks for different stages of drying were observed. A distinct different T peak was observed for every sample when a was less than 0.6. This prominent peak observed at less than 1\ua0ms relaxation time enabled us to conclude that the product a is less than 0.6. A completely different effect of sugar and salt on LF-NMR spectra were also reported. A strong correlation between a and total area (A ) was observed with the correlation coefficient = 0.695 to 0.971

Application of power ultrasound in freezing and thawing processes: effect on process efficiency and product quality

Freezing is one of the most efficient preservation approaches applied to food products and thawing is the reverse process of freezing. However, traditional freezing / thawing methods have low process efficiency. The application of ultrasound is a potential supplementary technique to improve the performance of both freezing and thawing processes of foods. Application of power ultrasound is able to better maintain the microstructure, reduce drip loss, decrease color and texture changes and retain some natural nutrients of foods during freezing. Meanwhile, quality improvement is also observed in food items thawed by ultrasound-assisted thawing methods. The fundamentals and the influences of ultrasound on the freezing and thawing processes of foods are demonstrated in this review article, from the aspects of efficiency enhancement and quality improvement

Screening of Single-Stranded DNA Aptamer Specific for Florfenicol and Application in Detection of Food Safety

In this work, the single-stranded DNA (ssDNA) aptamers specific to florfenicol (FF) and having a high binding affinity were prepared using the magnetic bead-based systematic evolution of ligands by the exponential enrichment technique (MB-SELEX). After 10 rounds of the MB-SELEX screening, aptamers that can simultaneously recognize FF and its metabolite florfenicol amine (FFA) were obtained. The aptamer with the lowest dissociation constant (Kd) was truncated and optimized based on a secondary structure analysis. The optimal aptamer selected was Apt-14t, with a length of 43 nt, and its dissociation constant was 4.66 ± 0.75 nM, which was about 7 times higher than that of the full-length sequence. The potential binding sites and interactions with FF were demonstrated by molecular docking simulations. In addition, a colorimetric strategy for nanogold aptamers was constructed. The linear detection range of this method was 0.00128–500 ng/mL and the actual detection limit was 0.00128 ng/mL. Using this strategy to detect florfenicol in actual milk and eggs samples, the spiked recoveries were 88.9–123.1% and 84.0–112.2%, respectively, and the relative standard deviation was less than 5.6%, showing high accuracy

Efficient plant foods processing based on infrared heating

Infrared (IR) heating is a potential energy-saving and high-efficiency technology, whose application in the food processing field is still in its infancy. IR heating has prominent advantages over conventional heating, namely, uniform heating in a shorter time with less quality degradation, but it has a salient shortcoming of low penetration depth, which makes it unsuitable for heating large or thick food materials. Efficient IR processing is to maximize the advantages of IR heating, and to overcome its shortcomings for achieving the goal of producing high-quality foods efficiently. In order to open up a broader path for IR processing in foods, this article reviews approaches to realizing efficient IR processing and introduces main applications as well as research progress of high-efficiency IR technology. Finally, some trends about the development of IR processing are also presented

Edible flowers: review of flower processing and extraction of bioactive compounds by novel technologies

Edible flowers have a long history of consumption in the form of vegetable flowers, fruit flowers or aromatic flowers. Because of their colorful and flavorful nature, edible flowers are believed to contain various nutritional and bioactive components. Today, people are advocating to eat nutritious food and paying attention to healthy foods, flower foods have become a new fashion diet trend. Although edible flowers have great sensory attraction, they have not used in food yet as widely as fresh vegetables and fruits have. The extremely short shelf-life limits the commercial use of edible flowers. In order to find some novel processing technologies which can extend the shelf-life and ensure the commercial use of flowers, we summarized the data of more than 100 studies performed until now on edible flowers. This review concludes emerging technologies including modified atmosphere packaging, high hydrostatic pressure, irradiation and edible coating to keep flower fresh, drying technologies including microwave drying, freeze drying and hybrid drying to maintain the optimal state of flower materials, as well as different extraction methods to extract the bioactive compounds and the microencapsulation of these compounds

Effect of combined chlorogenic acid and chitosan coating on antioxidant, antimicrobial, and sensory properties of snakehead fish in cold storage

Degradation of meat quality has always been a burning issue in fish preservation. To maintain the quality, a novel combination of chlorogenic acid (CGA) and chitosan (CS) coating was applied to snakehead fish fillets. Fish fillets were soaked into 2% chitosan (2CS), 0.2% CGA in 2% chitosan (0.2CGA/2CS), 0.5% CGA in 2% chitosan (0.5CGA/2CS), or 1.0% CGA in 2% chitosan (1.0CGA/2CS) solution; and then, coated samples were vacuum-packaged and stored at 2 ± 0.5°C. pH values, color values, microbial loads, hardness, sensory qualities, and oxidization of lipids and proteins of stored fish fillets were investigated for 5 months. Antimicrobial activity was found to be nonsignificant (p ≤ .05) among different coated fish fillets, while color, antioxidant, and pH values were significantly (p ≤ .05) different. Lipid oxidation and protein oxidation were found to be inhibited in 2CS-, 0.5CGA/2CS- and 1.0CGA/2CS-coated fish fillet. All CGA/CS coating delayed increase in pH (p ≤ .05) and resulted brown color. However, only CS coating resulted in higher sensory scores (p ≤ .05) and controlled browning. Considering antioxidant properties and other quality parameters, CGA/CS coating might be applied commercially in fish preservation

Smartphone-Based Image Analysis for Rapid Evaluation of Kiwifruit Quality during Cold Storage

As a vitamin C–rich fruit, choosing the eating time for kiwifruit with the best quality during the shelf period is still a problem for consumers. This paper mainly focuses on the correlation between cold storage time, quality indexes, volatile flavor compounds of postharvest kiwifruit and RGB value readouts from photos taken by mobile phone. Results indicated that the R to B ratio values (Central R/B) and B to G ratio values (Central B/G) of the central site of kiwifruit were strongly associated with storage time and all quality indicators. The central R/B was negatively correlated with titratable acidity, vitamin C and 2,6-Nonadienal contents and firmness and positively correlated with storage time, weight loss, soluble solids content, total soluble sugars, total plate counts and 1,3-Cyclooctadiene. We provide a novel and smart strategy to predict the shelf life and quality parameters of kiwifruit by capturing and calculating RGB values using a smartphone

Pear pomace soluble dietary fiber ameliorates the negative effects of high-fat diet in mice by regulating the gut microbiota and associated metabolites

The gut microbiota and related metabolites are positively regulated by soluble dietary fiber (SDF). In this study, we explored the effects of SDF from pear pomace (PP) on the regulation of gut microbiota and metabolism in high-fat-diet-fed (HFD-fed) C57BL/6J male mice. The results showed that PP-SDF was able to maintain the HFD disrupted gut microbiota diversity with a significant increase in Lachnospiraceae_UCG-006, Akkermansia, and Bifidobacterium spp. The negative effects of high-fat diet were ameliorated by PP-SDF by regulating lipid metabolisms with a significant increase in metabolites like isobutyryl carnitine and dioscoretine. Correlation analysis revealed that gut microbiota, such as Akkermansia and Lachnospiraceae_UCG-006 in the PP-SDF intervention groups had strong positive correlations with isobutyryl carnitine and dioscoretin. These findings demonstrated that PP-SDF interfered with the host's gut microbiota and related metabolites to reduce the negative effects caused by a high-fat diet