The present study’s aims of isolation, characterization and in vitro antioxidant activity screening of pure compound from Black pepper (Piper nigrum) were investigated. Nowadays, scientific exploration of medicinal plants from natural sources has become the prime concern globally. All the crude drugs that have been isolated from natural plant origin (herbs, root, stem, bark, fruit and flower) have great significance in drug discovery as well as a lead compound to demonstrate great synergistic effect on pharmacology. For this research work, methanol was selected as a mother solvent, and the crude methanolic extract of black pepper was partitioned in between the solvent chloroform and di-ethyl-ether. A crystal fraction has been eradicated from the chloroform extract of black pepper (Piper nigrum). The crystal compound (C₁) was isolated and purified by using thin layer chromatography (TLC) and recrystallization technique. The purified crystal compound (C₁) isolated from black pepper possesses a strong in vitro antioxidant activity. The IC₅₀ value of crystal compound (C₁) was 4.1 µg/ml where the standard one had 3.2 µg/ml. Physical, phytochemical and chromatographical characterization of pure crystal compound (C₁) has been explored, and from the analysis of all characteristics, it was found that, crystal compound (C₁) might have resembling features of the standard Piperine of black pepper. The overall research work was really remarkable and introduced a convenient way of isolating pure compound from the natural source which will be a great referential resource in isolating crude drugs for future analysis.

Consumers demand clean-label food products, necessitating the search for new, natural antimicrobials to meet this demand while ensuring food safety. This review aimed at investigating the antimicrobial properties of black pepper (Piper guineense) against foodborne microorganisms. The existence of foodborne illness, food spoilage, food waste, the resulting negative economic impact of these issues, and consumer interests have all pushed the food industry to find alternative, safe, and natural antimicrobials to be used in foods and beverages. Consumers have also influenced the demand for novel antimicrobials due to the perceived association of current synthetic preservatives with diseases and adverse effects on children. They also have a desire for clean-label products. These combined concerns have prompted researchers at investigating plant extracts as potential sources for antimicrobials. Plants possess many antimicrobial properties; therefore, evaluating these plant extracts as a natural source of antimicrobials can lead to a preventative control method in reducing foodborne illness and food spoilage, inclusively meeting consumer needs. In most regions, P. guineense is commonly utilized due to its potent and effective medicinal properties against foodborne microorganisms.

The aim of this study was to evaluate and compare the antioxidant potential of essential oils of some commonly used Indian spices (black pepper, cinnamon, clove, coriander and cumin) in various in vitro models and in food supplements enriched with omega-6 and omega-3 fatty acids. In vitro antioxidant potential was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging and Fe²⁺ ion-chelating methods and lipid oxidation stabilisation potential was evaluated in bulk soybean oil-fish oil mixture and their oil-in-water emulsions using peroxide value (PV), p-anisidine value (p-AV) and total oxidation value as indicators of oxidation. Combination effects using DPPH radical scavenging and Briggs-Rauscher oscillating reaction methods were also evaluated. Test essential oils showed varying degrees of radical scavenging and Fe²⁺ ion-chelating efficacy. Clove and coriander oils showed significantly higher (P < 0.05) radical scavenging and Fe²⁺ ion-chelating potential over other tested essential oils as well as BHT and ∞-tocopherol. The anti-lipid peroxidative potential of test essential oils was found in the following decreasing order: clove > coriander > BHT > cinnamon > α-tocopherol > cumin > black pepper. Furthermore, clove and coriander oils showed synergistic antioxidant activity in combination both in DPPH radical scavenging and Briggs-Rauscher oscillating reaction methods whereas other possible combinations showed additive effects. Strong radical scavenging and Fe²⁺-chelating as well as anti-lipid peroxidative activities of clove and coriander oils provide evidence that clove and coriander oils may serve as a potential source of natural antioxidants for retarding lipid oxidation of food supplements enriched with omega-6 and omega-3 fatty acids.