Harnessing the power of resistant starch: a narrative review of its health impact and processing challenges

Starch is a primary energy storage for plants, making it an essential component of many plant-based foods consumed today. Resistant starch (RS) refers to those starch fractions that escape digestion in the small intestine and reach the colon where they are fermented by the microflora. RS has been repeatedly reported as having benefits on health, but ensuring that its content remains in food processing may be challenging. The present work focuses on the impact RS on health and explores the different processes that may influence its presence in foods, thus potentially interfering with these effects. Clinical evidence published from 2010 to 2023 and studying the effect of RS on health parameters in adult populations, were identified, using PUBMED/Medline and Cochrane databases. The search focused as well on observational studies related to the effect of food processes on RS content. While processes such as milling, fermentation, cooking and heating seem to have a deleterious influence on RS content, other processes, such as cooling, cooking time, storage time, or water content, may positively impact its presence. Regarding the influence on health parameters, there is a body of evidence suggesting an overall significant beneficial effect of RS, especially type 1 and 2, on several health parameters such as glycemic response, insulin resistance index, bowel function or inflammatory markers. Effects are more substantiated in individuals suffering from metabolic diseases. The effects of RS may however be exerted differently depending on the type. A better understanding of the influence of food processes on RS can guide the development of dietary intake recommendations and contribute to the development of food products rich in RS.

New Genomic Techniques applied to food cultures: a powerful contribution to innovative, safe, and sustainable food products

Nontransgenic New Genomic Techniques (NGTs) have emerged as a promising tool for food industries, allowing food cultures to contribute to an innovative, safe, and more sustainable food system. NGTs have the potential to be applied to microorganisms, delivering on challenging performance traits like texture, flavour, and an increase of nutritional value. This paper brings insights on how nontransgenic NGTs applied to food cultures could be beneficial to the sector, enabling food industries to generate innovative, safe, and sustainable products for European consumers. Microorganisms derived from NGTs have the potentials of becoming an important contribution to achieve the ambitious targets set by the European 'Green Deal' and 'Farm to Fork' policies. To encourage the development of NGT-derived microorganisms, the current EU regulatory framework should be adapted. These technologies allow the introduction of a precise, minimal DNA modification in microbial genomes resulting in optimized products carrying features that could also be achieved by spontaneous natural genetic evolution. The possibility to use NGTs as a tool to improve food safety, sustainability, and quality is the bottleneck in food culture developments, as it currently relies on lengthy natural evolution strategies or on untargeted random mutagenesis.

Acute toxicity, toxicokinetics, and tissue target of lead and uranium in the clam Corbicula fluminea and the worm Eisenia fetida: comparison with the fish Brachydanio rerio

The general objective of our work was to propose new reference material for chemical toxicity testing and new sentinel organisms for environmental quality survey programs (freshwater or soils). We also wanted to provide basic toxicological data on the environmental effects of uranium. Thus, we conducted a comparative study to establish the acute toxicity and toxicokinetics of lead (Pb) and uranium (U) to the bivalve mollusc Corbicula fluminea and the terrestrial annelid Eisenia fetida andrei and to compare these findings with those of the well-known teleost fish Brachydanio rerio. We then measured the concentration of these metals in various tissues of the clam and the worm after two periods of exposure (4 and 11 days) to identify the affinities of these tissues for Pb and U. Our results have shown that Pb and U are very toxic to Eisenia and relatively nontoxic to Corbicula. By comparison, Pb was relatively nontoxic and U appeared to be very toxic to the fish. The toxicokinetic studies indicated that the three species are able to accumulate Pb and U, the rate and level of accumulation depending both on the species and the metal. We also found that fish and clams depurate the two metals. Data collected for the worm were conflicting: Pb was not depurated whereas tissue concentrations of U declined after the eighth day of exposure. Our study has also shown that the tissue distribution of Pb in the mollusc and in the earthworm differs significantly from that of U, both after 4 and 11 days exposure. In conclusion, these three species showed potential as bioindicators of environmental contamination by metals. Indeed, they could be used in conjunction to test different compartments of an ecosystem: worms for soils, fish for the water column, and clams for the water/sediment interface.

Characterization of a 14 kDa plant-related serine protease inhibitor and regulation of cytotoxic activity in earthworm coelomic fluid

We have purified and characterized the serine protease inhibitor activity contained in the coelomic fluid of the earthworms, Eisenia. Serine protease inhibitor activity was stable between pH3 and 9.5, not flocculable by pH 3.0 and resistant to 100 degrees C for 15 min. or to 4 degrees C for 24 h. Ten microL of coelomic fluid was sufficient to inhibit in vitro the protease activity of 0.12 microgram of trypsin. Injection of living bacteria into earthworms resulted in increased serine protease activity 1-2 days post-injection, and increased serine protease inhibitor activity on day 4, suggesting that serine protease inhibitor is responsible for serine protease neutralization. Purified to homogeneity by affinity chromatography on trypsin, the serine protease inhibitor of Eisenia is a monomer of 14 kDa. Its partial NH2 amino acid sequence revealed a basic hydrophobic fragment which shared 68-75% homologies and 47-60% identities with several plant serine protease inhibitors. Eisenia cytotoxic activity due to the two fetidins of 40 and 45 kDa was stimulable in vitro by several serine proteases. Incubation with soybean trypsin inhibitor variant a (STIa) resulted in less cytotoxicity. The inhibitory effect occurred only when STIa was added before cell disruption. Interpretative cytotoxic scheme involving the release of intracellular cytotoxic proteins, intracellular trypsin-like activator and extracellular serine protease inhibitor suggests regulatory mechanisms for cellular/humoral immune system of earthworms.

Immuno-Modulator Effects of Carbaryl and 2,4 D in theEarthworm Eisenia fetida andrei

Carbaryl and 2,4 dichlorophenoxy acetic acid (2,4 D)exerted differential effects on the earthworm E. f. andrei functionsrelated to immuno defense. As determined by contact test assay, carbarylactivity is characterized by a low LC50 value of 3.4 &mgr;g/cm2,compared to 18 &mgr;g/cm2 for 2,4 D. Incubating earthworms withdoses of carbaryl as low as 0.1 &mgr;g/cm2 resulted in theinhibition of the lysozyme activity detected in the cytosol (CL). A stronginhibition of phagocytosis was also obtained but with 1.5&mgr;g/cm2. On the other hand, low doses of carbaryl significantlystimulated cytolysis (0.1 &mgr;g/cm2), serine protease activity (0.1&mgr;g/cm2) in the coelomic fluid (CF) and serine protease activityin the CL (0.05 &mgr;g/cm2). Concerning 2,4 D, both cytolysis in theCF and serine protease activity in the CL were stimulated by respectively 3.5&mgr;g/cm2 and 18 &mgr;g/cm2. Phagocytosis was inhibitedonly with 18 &mgr;g/cm2. Lysozyme and serine protease inhibitoractivities were not affected. The immuno toxicological assays we developed inearthworms, allow to distinguish between chemicals with differentimmuno-modulatory properties. Moreover, earthworms appear to be aparticularly well adapted sentinel organism for the evaluation of soilcontamination.

PCBs increase molecular-related activities (lysozyme, antibacterial, hemolysis, proteases) but inhibit macrophage-related functions (phagocytosis, wound healing) in earthworms

Both humoral and cellular immunodefense responses of the earthworms, Eisenia fetida andrei, Eisenia hortensis, and Lumbricus terrestris, have been compared after exposure to the PCB Aroclor 1254. Responses mediated by free factors, detected by in vitro assays for lysozyme, hemolysis, and proteases, were increased in both Eisenia. Antibacterial activity directed against pathogenic bacteria was increased in E.f. andrei. The resistance of L. terrestris against non-pathogenic bacteria was decreased, confirming that the bacteria were treated by different systems according to their pathogenicity. Nonspecific cellular functions, including phagocytosis and those related to wound healing, decreased dramatically in all earthworms.