Single and interactive effects of process variables on microwave-assisted and conventional extractions of antioxidants from vegetable solid wastes

Health Benefits of Key Constituents in Cichorium intybus L

The genus Cichorium (Asteraceae) that originates from the Mediterranean area consists of six species (Cichorium intybus, Cichorium frisee, Cichorium endivia, Cichorium grouse, Cichorium chico and Cichorium pumilum). Cichorium intybus L., commonly known as chicory, has a rich history of being known as a medicinal plant and coffee substitute. A variety of key constituents in chicory play important roles as antioxidant agents. The herb is also used as a forage plant for animals. This review highlights the bioactive composition of C. intybus L. and summarizes the antioxidant activity associated with the presence of inulin, caffeic acid derivatives, ferrulic acid, caftaric acid, chicoric acid, chlorogenic and isochlorogenic acids, dicaffeoyl tartaric acid, sugars, proteins, hydroxycoumarins, flavonoids and sesquiterpene lactones. It also covers the plant's occurrence, agriculture improvement, natural biosynthesis, geographical distribution and waste valorization.

Optimization of the Accelerated Solvent Extraction of Caffeoylquinic Acids from Forced Chicory Roots and Antioxidant Activity of the Resulting Extracts

Forced chicory roots (FCR) are the main but also the least valued by-products of Belgian endive culture. However, they contain molecules of interest for industry such as caffeoylquinic acids (CQAs). This study aims to investigate accelerated solvent extraction (ASE) as a green technique to recover chlorogenic acid (5-CQA) and 3,5-dicaffeoylquinic acid (3,5-diCQA), the main CQAs. A D-optimal design was used to determine the influence of temperature and ethanol percentage on their extraction. Optimal extraction conditions were determined using response surface methodology (RSM) and allow the recovery of 4.95 ± 0.48 mg/gDM of 5-CQA at 107 °C, 46% of ethanol and 5.41 ± 0.79 mg/gDM of 3,5-diCQA at 95 °C, 57% of ethanol. The antioxidant activity of the extracts was also optimized by RSM. The highest antioxidant activity was achieved at 115 °C with 40% ethanol (more than 22mgTrolox/gDM). Finally, correlation between the antioxidant activity and the amount of CQAs was determined. FCR can be a great source of bioactive compounds with potential use as biobased antioxidant.

Recovery of Chlorogenic Acids from Agri-Food Wastes: Updates on Green Extraction Techniques

The agri-food sector produces a huge amount of agri-food wastes and by-products, with a consequent great impact on environmental, economic, social, and health aspects. The reuse and recycling of by-products represents a very important issue: for this reason, the development of innovative recovery and extraction methodologies must be mandatory. In this context of a circular economy, the study of green extraction techniques also becomes a priority in substitution of traditional extraction approaches. This review is focused on the recovery of chlorogenic acids from agri-food wastes, as these compounds have an important impact on human health, exhibiting several different and important healthy properties. Novel extraction methodologies, namely microwave and ultrasound-assisted extractions, supercritical fluid extraction, and pressurized-liquid extraction, are discussed here, in comparison with conventional techniques. The great potentialities of these new innovative green and sustainable approaches are pointed out. Further investigations and optimization are mandatory before their application in industrial processes.

Valorization of Bio-Residues from the Processing of Main Portuguese Fruit Crops: From Discarded Waste to Health Promoting Compounds

Food processing generates a large amount of bio-residues, which have become the focus of different studies aimed at valorizing this low-cost source of bioactive compounds. High fruit consumption is associated with beneficial health effects and, therefore, bio-waste and its constituents arouse therapeutic interest. The present work focuses on the main Portuguese fruit crops and revises (i) the chemical constituents of apple, orange, and pear pomace as potential sources of functional/bioactive compounds; (ii) the bioactive evidence and potential therapeutic use of bio-waste generated in the processing of the main Portuguese fruit crops; and (iii) potential applications in the food, nutraceutical, pharmaceutical, and cosmetics industries. The current evidence of the effect of these bio-residues as antioxidant, anti-inflammatory, and antimicrobial agents is also summarized. Conclusions of the revised data are that these bio-wastes hold great potential to be employed in specific nutritional and pharmaceutical applications.

Biomolecules from municipal and food industry wastes: An overview

Biological wastes generated from food and fruit processing industries, municipal markets, and water treatment facilities are a major cause of concern for Health Departments and Environmentalists around the world. Conventional means of managing these wastes such as transportation, treatment, and disposal, are proving uneconomical. The need is to develop green and sustainable technologies to circumvent this ever-growing and persistent problem. In this article, the potential of diverse microbes to metabolize complex organic rich biowastes into a variety of bioactive compounds with diverse biotechnological applications have been presented. An integrated strategy has been proposed that can be commercially exploited for the recovery of value-adding products ranging from bioactive compounds, chemical building blocks, energy rich chemicals, biopolymers and materials, which results in a self-sustaining circular bioeconomy with nearly zero waste generation and complete degradation.

Technology and Process Design for Phenols Recovery from Industrial Chicory (Chicorium intybus) Leftovers

Vegetal leftovers from the agro-food industry represent a huge source of primary and secondary metabolites, vitamin, mineral salts and soluble as well as insoluble fibers. Economic reports on the growth in the polyphenol market have driven us to focus our investigation on chicory (Chicorium intybus L.), which is one of the most popular horticultural plants in the world and a rich source of phenolic compounds. Ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and their simultaneous combination, using either ethanol/water or water alone (also sub-critical), have been investigated with the aim of designing a green and efficient extraction process. Higher total-polyphenol yields as well as dramatic reductions in extraction times and solvent consumption have been obtained under these conditions. ANOVA test for analyses of variance followed by the Tukey honestly significant difference (HSD) post-hoc test of multiple comparisons was used in the statistical analysis. MAE experiments performed with sub-critical water, and MW/US experiments with an ethanol solution have shown polyphenol recovery values of up to ~3 g of gallic acid equivalents (GAE) per kg of fresh material in only 15 min, while conventional extraction required 240 min to obtain the same result.

Bioassay-guided isolation, identification of compounds from Origanum rotundifolium and investigation of their antiproliferative and antioxidant activities

CONTEXT

Origanum (Lamiaceae) has been used in food and pharmaceutical industries.

OBJECTIVE

Isolation and identification of bioactive compounds from Origanum rotundifolium Boiss. and investigation of their antiproliferative and antioxidant activities.

MATERIALS AND METHODS

The aerial part of O. rotundifolium was dried and powdered (1.0 kg ±2.0 g) then extracted with hexane, ethyl acetate, methanol and water. Solvent (3 × 1 L) was used for each extraction for a week at room temperature. The aqueous extract was partitioned with ethyl acetate (3 × 1 L) to yield the water/EtOAc extract subjected to chromatography to isolate the active compounds. The structures of isolated compounds were elucidated by 1 D, 2 D NMR and LC-TOF/MS.

RESULTS

Apigenin (1), ferulic acid (2), vitexin (3), caprolactam (4), rosmarinic acid (5), and globoidnan A (6) were isolated and identified. Globoidnan A (6), vitexin (3), and rosmarinic acid (5) revealed the excellent DPPH^• scavenging effect with IC₅₀ values of 22.4, 31.4, 47.2 μM, respectively. Vitexin (3) (IC₅₀ 3.6), globoidnan A (6) (IC₅₀ 4.6), apigenin (1) (IC₅₀ 8.9) and ferulic acid (2) exhibited more ABTS^•+ activity than standard Trolox (IC₅₀ 13.8 μg/mL). Vitexin (3) revealed the most antiproliferative activity against HeLa, HT29, C6 and Vero cells lines with IC₅₀ values of 35.6, 32.5, 41.6, 46.7 (μM), respectively.

DISCUSSION AND CONCLUSION

Globoidnan A (6) has the most antioxidant effects on all assays. This has to do with the chemical structure of the compound bearing the acidic protons. Vitexin (3) could be a promising anticancer agent.

Cauliflower waste utilization for sustainable biobutanol production: revelation of drying kinetics and bioprocess development

Efficient yet economic production of biofuel(s) using varied second-generation feedstock needs to be explored in the current scenario to cope up with global fuel demand. Hence, the present study was performed to reveal the use of cauliflower waste for acetone-butanol-ethanol (ABE) production using Clostridium acetobutylicum NRRL B 527. The proximate analysis of cauliflower waste demonstrated to comprise 17.32% cellulose, 9.12% hemicellulose, and 5.94% lignin. Drying of cauliflower waste was carried out in the temperature range of 60-120 °C to investigate its effect on ABE production. The experimental drying data were simulated using moisture diffusion control model. The cauliflower waste dried at 80 °C showed maximum total sugar yield of 26.05 g L^-1. Furthermore, the removal of phenolics, acetic acid, and total furans was found to be 90-97, 10-40, and 95-97%, respectively. Incidentally, maximum ABE titer obtained was 5.35 g L^-1 with 50% sugar utilization.

A New Age for Quercus spp. Fruits: Review on Nutritional and Phytochemical Composition and Related Biological Activities of Acorns

The current global food system must adapt to the expected growth of world population (about 9 billion individuals by 2050). This adaptation will probably include an increased consumption of edible wild foods, due to their richness in micronutrients and bioactive compounds, besides providing a cost-effective and sustainable way of improving caloric food security. A striking example of such natural matrices is the Quercus genus, which has the additional advantage of being widespread throughout the Northern Hemisphere. In a traditional sense, Quercus fruits (acorns) were mainly used in animal feeding, despite their potentially important role on the rural economy. But this preconception is changing. In fact, their nutritional value, high contents in phytochemical compounds, biological activity (such as antioxidant, anticarcinogenic, and cardioprotective properties) and use in the treatment of specific diseases (such as atherosclerosis, diabetes, or Alzheimer's disease) have raised the interest in integrating acorns into the human diet. Accordingly, this comprehensive overview was designed to provide an evidence-based review of the literature, with the objective to achieve useful conclusions regarding the nutritional properties, methodologies of extraction, identification, and characterization of a wide variety of bioactive compounds and scientifically validated bioactivities in Quercus species worldwide. The industrial by-products from acorn oil extraction or flour production are also included. Data regarding the analytical techniques, individual compounds, and their bioactivities, are organized in tables. The reported data are discussed and directions for further investigations are suggested, highlighting the use of acorns in food, nutraceutical, and pharmaceutical applications.

Effect of ultrasound on the extraction of total anthocyanins from Purple Majesty potato

This study examined anthocyanin extraction using the application of ultrasound to raw freeze dried, microwaved and raw sliced Purple Majesty potato, a new pigmented potato variety rich in anthocyanins. A 20 kHz probe was used for the sonication at 3 different amplitudes (30%, 50% and 70%) and ethanol in water at different ratios (50:50 and 70:30 v/v) was used for the extraction. Anthocyanin extraction from raw freeze dried purple potato was optimal at an ethanol:water ratio (70:30; v/v) after 5 min of ultrasonication, while the least amount of anthocyanins was extracted from raw sliced potatoes. The application of microwaves (as a pre-treatment) before the UAE resulted in an increase in the amount of anthocyanins extracted and a decrease in the amount of solvent used. Analysis of variance showed that potato form, ultrasonication time, ultrasonication amplitude and solvent ratio as well as two and three way interactions between some of these factors had a very significant effect (p<0.000) on the amount of anthocyanins extracted.

Extraction and analysis of antioxidant compounds from the residues of Asparagus officinalis L

Asparagus residues were used as materials to obtain antioxidant compounds by solid-liquid extraction in this study. The effects of different extraction parameters including extraction solvents, time, temperature and liquid-solid ratio on the contents of total flavonoids, total phenolics and total antioxidant activity were investigated. Antioxidant activity of the extract from asparagus residues was evaluated by HPLC- ABTS · (+) and the bioactive components were identified by HPLC- MS/MS. The results showed that the extraction yield was significantly influenced (P < 0.05) by solvent composition, extraction time and temperature. The appropriate parameters were preferred as extraction solvent of 50 % ethanol with liquid-solid ratio of 30:1, extraction temperature of 80 °C and time of 2 h. Antioxidant activity evaluation of the extract indicated flavonoids and phenolics were dominant bioactive compounds. Five antioxidant compounds were identified as ferulic acid, kaempferol, quercetin, rutin and isorhamnetin.

Recovery of biomolecules from food wastes--a review

Food wastes are produced by a variety of sources, ranging from agricultural operations to household consumption. About 38% occurs during food processing. At present, the European Union legislation encourages the exploitation of co-products. This valorisation can be achieved through the extraction of high-value components such as proteins, polysaccharides, fibres, flavour compounds, and phytochemicals, which can be re-used as nutritionally and pharmacologically functional ingredients. Extraction can proceed according to solid-liquid extraction, Soxhlet extraction, pressurized fluid extraction, supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pulsed electric field extraction, and enzyme-assisted extraction. Nevertheless, these techniques cannot be used indiscriminately and their choice depends on the type of biomolecules and matrix, the scale processing (laboratory or industrial), the ratio between production costs and economic values of the compounds to be extracted. The vegetable wastes include trimmings, peelings, stems, seeds, shells, bran, residues remaining after extraction of oil, starch, sugar, and juice. The animal-derived wastes include wastes from bred animals, wastes from seafood, wastes from dairy processing. The recovered biomolecules and by-products can be used to produce functional foods or as adjuvants in food processing or in medicinal and pharmaceutical preparations. This work is an overview of the type and amounts of food wastes; food waste legislation; conventional and novel techniques suitable for extracting biomolecules; food, medicinal and pharmaceutical uses of the recovered biomolecules and by-products, and future trends in these areas.