Supercritical CO2 extraction of spices: A systematic study with focus on terpenes and piperamides from black pepper (Piper nigrum L.)

Composing functional food from agro-forest wastes: Selectively extracting bioactive compounds using supercritical fluid extraction

Supercritical fluid extraction (SFE) employing carbon dioxide (SC-CO2) is an efficient method to extract bioactive compounds from agro-forest wastes. These compounds maintain and/or improve food nutrition, safety, freshness, taste, and health and are employed as natural functional food components. To highlight the potential of this technology, we focus on the following current advances: (I) parameters affecting solubility in SFE (pressure, temperature, SC-CO2 flow rate, extraction time, and co-solvents); (II) extraction spectra and yield obtained according to proportion and composition of co-solvents; (III) extract bioactivity for functional food production. Fatty acids, monoterpenes, sesquiterpenes, diterpenoids, and low-polarity phenolic acids and triterpenoids were extracted using SFE without a co-solvent. High-polarity phenolic acids and flavonoids, tannins, carotenoids, and alkaloids were only extracted with the help of co-solvents. Using a co-solvent significantly improved the triterpenoid, flavonoid, and phenolic acid yield with a medium polarity.

Piperine: Chemistry and Biology

Piperine is a plant-derived promising piperamide candidate isolated from the black pepper (Piper nigrum L.). In the last few years, this natural botanical product and its derivatives have aroused much attention for their comprehensive biological activities, including not only medical but also agricultural bioactivities. In order to achieve sustainable development and improve survival conditions, looking for environmentally friendly pesticides with low toxicity and residue is an extremely urgent challenge. Fortunately, plant-derived pesticides are rising like a shining star, guiding us in the direction of development in pesticidal research. In the present review, the recent progress in the biological activities, mechanisms of action, and structural modifications of piperine and its derivatives from 2020 to 2023 are summarized. The structure-activity relationships were analyzed in order to pave the way for future development and utilization of piperine and its derivatives as potent drugs and pesticides for improving the local economic development.

Chemical Composition of Essential Oils and Supercritical Carbon Dioxide Extracts from Amomum kravanh, Citrus hystrix and Piper nigrum 'Kampot'

The fruits of Amomum kravanh, Citrus hystrix and Piper nigrum 'Kampot' are traditionally used as spices in Cambodian cuisine. In this study, the chemical composition of essential oils (EOs) and supercritical CO2 extracts from all three species was determined using GC-MS, with two columns of different polarity (HP-5/DB-HeavyWAX). Differences between the chemical profile of the EOs and CO2 extracts were observed for all species. The greatest difference was detected in A. kravanh EO containing mainly eucalyptol (78.8/72.6%), while the CO2 extract was rich in fatty acids (13/55.92%) and long-chain alkanes (25.55/9.54%). Furthermore, the results for the CO2 extract of this species differed, where tricosane (14.74%) and oleic acid (29.26%) were the main compounds identified when utilizing the HP-5 or DB-HeavyWAX columns, respectively. Moreover, the EO and CO2 extract from P. nigrum 'Kampot' fruits and the CO2 extract from C. hystrix fruit peel, containing respective amounts 34.84/39.55% (for EO) and 54.21/55.86% (for CO2 extract) of β-caryophyllene and 30.2/28.9% of β-pinene, were isolated and analyzed for the first time. Generally, these findings suggest that supercritical CO2 could potentially be used for the extraction of all three spices. Nevertheless, further research determining the most efficient extraction parameters is required before its commercial application.

Value-Added Compounds with Antimicrobial, Antioxidant, and Enzyme-Inhibitory Effects from Post-Distillation and Post-Supercritical CO2 Extraction By-Products of Rosemary

Hydrodistillation is the main technique to obtain essential oils from rosemary for the aroma industry. However, this technique is wasteful, producing numerous by-products (residual water, spent materials) that are usually discarded in the environment. Supercritical CO₂ (SC-CO₂) extraction is considered an alternative greener technology for producing aroma compounds. However, there have been no discussions about the spent plant material leftover. Therefore, this work investigated the chemical profile (GC-MS, LC-HRMS/MS) and multi-biological activity (antimicrobial, antioxidant, enzyme inhibitory) of several raw rosemary materials (essential oil, SC-CO₂ extracts, solvent extracts) and by-products/waste materials (post-distillation residual water, spent plant material extracts, and post-supercritical CO₂ spent plant material extracts). More than 55 volatile organic compounds (e.g., pinene, eucalyptol, borneol, camphor, caryophyllene, etc.) were identified in the rosemary essential oil and SC-CO₂ extracts. The LC-HRMS/MS profiling of the solvent extracts revealed around 25 specialized metabolites (e.g., caffeic acid, rosmarinic acid, salvianolic acids, luteolin derivatives, rosmanol derivatives, carnosol derivatives, etc.). Minimum inhibitory concentrations of 15.6-62.5 mg/L were obtained for some rosemary extracts against Micrococcus luteus, Bacilus cereus, or Staphylococcus aureus MRSA. Evaluated in six different in vitro tests, the antioxidant potential revealed strong activity for the polyphenol-containing extracts. In contrast, the terpene-rich extracts were more potent in inhibiting various key enzymes (e.g., acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase, and glucosidase). The current work brings new insightful contributions to the continuously developing body of knowledge about the valorization of rosemary by-products as a low-cost source of high-added-value constituents in the food, pharmaceutical, and cosmeceutical industries.