Allicin (diallylthiosulfinate) is a defence molecule from garlic (Allium sativum L.) with a broad range of biological activities. Allicin is produced upon tissue damage from the non-proteinogenic amino acid alliin (S-allylcysteine sulfoxide) in a reaction that is catalyzed by the enzyme alliinase. Current understanding of the allicin biosynthetic pathway will be presented in this review. Being a thiosulfinate, allicin is a reactive sulfur species (RSS) and undergoes a redox-reaction with thiol groups in glutathione and proteins that is thought to be essential for its biological activity. Allicin is physiologically active in microbial, plant and mammalian cells. In a dose-dependent manner allicin can inhibit the proliferation of both bacteria and fungi or kill cells outright, including antibiotic-resistant strains like methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, in mammalian cell lines, including cancer cells, allicin induces cell-death and inhibits cell proliferation. In plants allicin inhibits seed germination and attenuates root-development. The majority of allicin’s effects are believed to be mediated via redox-dependent mechanisms. In sub-lethal concentrations, allicin has a variety of health-promoting properties, for example cholesterol- and blood pressure-lowering effects that are advantageous for the cardio-vascular system. Clearly, allicin has wide-ranging and interesting applications in medicine and (green) agriculture, hence the detailed discussion of its enormous potential in this review. Taken together, allicin is a fascinating biologically active compound whose properties are a direct consequence of the molecule’s chemistry.

Curcumin is a highly pleiotropic molecule found in the rhizomes of Curcuma longa (turmeric). It is responsible for the yellow color of turmeric and has been shown to inhibit the proliferation of cancer cells and to be of use in preventing or treating a number of diseases. Curcumin has been shown to modulate multiple cell-signaling pathways simultaneously, thereby mitigating or preventing many different types of cancers, including multiple myeloma and colorectal, pancreatic, breast, prostate, lung, head, and neck cancers, in both animal models and humans. Current therapeutic approaches using a single cancer drug for a single target can be expensive, have serious side effects, or both. Consequently, new approaches to the treatment and prevention of cancer, including the integration of curcumin as a viable treatment strategy where dysregulation of many pathways is involved, are warranted. A methodical review of the evidence was performed to evaluate the effects of curcumin in support of a health claim, as established through the regulatory framework of Health Canada, for a relationship between the consumption of curcumin and the prevention and treatment of cancer.

Globally, the production, distribution, sale and consumption of plant-based foods (PBFs) are on the increase due to heightened consumer awareness, a growing demand for clean label products, widespread efforts to promote and embrace sustainable practices, and ethical concerns over animal-derived counterparts. This has led to the exploration of several strategies by researchers and the food industry to develop alternative milk, cheese, meat, and egg products from various plant-based sources using technologies such as precision fermentation (PF), scaffolding, extrusion, and muscle fibre simulation. This work explores current alternative protein sources and PBFs, production trends, innovations in formulation, nutritional quality, as well as challenges restricting full utilization and other limitations. However, PBFs have several limitations which constrain their acceptance, including the beany flavour of legumes, concerns about genetically modified foods, cost, nutritional inadequacies associated micronutrient deficiencies, absence of safety regulations, and the addition of ingredients that are contrary to their intended health-promoting purpose. The review concludes that investing in the development of PBFs now, has the potential to facilitate a rapid shift to large scale consumption of sustainable and healthy diets in the near future. Graphical Abstract

Antioxidants remain interesting molecules of choice for suppression of the toxic effects of free radicals in foods and human systems. The current practice involves the use of mainly synthetic molecules as potent antioxidant agents. However, due to the potential negative impact on human health, there is an intensive effort within the research community to develop natural alternatives with similar antioxidant efficacy but without the negative side effects of synthetic molecules. Still, the successful development of new molecules depends on the use of reliable chemical or cell culture assays to screen antioxidant properties. Chemical antioxidant assays include the determination of scavenging ability against free radicals such as DPPH, superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, and nitric oxide. Other antioxidant tests include the ability of compounds to bind and sequester prooxidant metal cations, reduce ferric iron, and attenuate the rate of lipid oxidation. Ex vivo tests utilize cell cultures to confirm entry of the molecules into cells and the ability to quench synthetic intracellular free radicals or to stimulate the increased biosynthesis of endogenous antioxidants. In order to assist researchers in their choice of antioxidant evaluation methods, this review presents background scientific information on some of the most commonly used antioxidant assays with a comparative discussion of the relevance of published literature data to food science and human nutrition applications.