Publications by authors named "Sergio Medina-Godoy"

The production of second-generation bioethanol has several challenges, among them finding cheap and efficient enzymes for a sustainable process. In this work, we analyzed two native fungi, and , as a source of cellulolytic enzyme production, and corn stover, wheat bran, chickpeas, and bean straw as a carbon source in two fermentation systems: submerged and solid fermentation. Corn stover was selected for cellulase production in both fermentation systems, because we found the highest enzymatic activities when carboxymethyl cellulase activity (CMCase) was assessed using CMC as substrate.

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Tomato field wastes and industrial by-products represents a valuable source of compounds with nutraceutical potential, and therefore of raw material to obtain food ingredients and additives. The objective of this study was to obtain a flour from tomato industrial by-product and from tomato field waste, dried by a conventional method, that allows to remain important nutraceutical compounds, which in the future, can be used for biotechnological purposes. We found that the drying procedure that allowed to reach an adequate water activity (0.

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The aim of this study was to isolate, identify and quantify soluble free phenolics, conjugated acid-hydrolysable phenolics (AHP) and alkaline-hydrolysable phenolics, and bound phenolics (BP) fractions from two tomato varieties (saladette and grape) and an industrial tomato by-product, as well as, to determine their antioxidant capacity. Phenolic composition was determined using Folin-Ciocalteu's method and HPLC-DAD. AHP were predominant in grape and saladette tomato extracts (91.

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Bioactive compounds and antioxidant activity were evaluated from industrial Jalapeño pepper byproducts and simulated non processed byproducts from two Mexican states (Chihuahua and Sinaloa) to determine their value added potential as commercial food ingredients. Aqueous 80% ethanol produced about 13% of dry extract of polar compounds. Total phenolic content increased and capsaicin and dihydrocapsaicin decreased on scalding samples (80 °C, 2 min) without affecting ascorbic acid.

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Article Synopsis
  • Jatropha curcas seed shells, a by-product of oil extraction, have gained attention for their chemical properties and potential uses.
  • The study identified and quantified various phenolic compounds in the shells, finding high levels of free, conjugate, and bound phenolics.
  • The methanolic extract from these shells demonstrated significant antioxidant activity, comparable to well-known antioxidants like Trolox and ascorbic acid, making it a promising source of natural antioxidants.
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The phenolic content and antioxidant and antimutagenic activities from the peel and seeds of different tomato types (grape, cherry, bola and saladette type), and simulated tomato industrial byproducts, were studied. Methanolic extracts were used to quantify total phenolic content, groups of phenolic compounds, antioxidant activities, and the profile of phenolic compounds (by HPLC-DAD). Antimutagenic activity was determined by Salmonella typhimurium assay.

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The arbuscular mycorrhizal (AM) symbiosis is an intimate association between specific soil-borne fungi and the roots of most land plants. AM colonisation elicits an enhanced defence resistance against pathogens, known as mycorrhizal-induced resistance (MIR). This mechanism locally and systemically sensitises plant tissues to boost their basal defence response.

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Background: The potential use of hard-to-cook (hardened) chickpeas to obtain value-added functional food ingredients was evaluated. For that purpose, some nutraceutical and functional attributes of several chickpea protein hydrolysates (CPHs) prepared from both fresh and hard-to-cook grains were evaluated.

Results: All the CPHs prepared from both fresh and hard-to-cook grains, with the enzymes alcalase, pancreatin and papain, showed high angiotensin converting enzyme inhibitory (ACE-I) activity with IC₅₀ values ranging from 0.

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Amarantin is the predominant seed storage protein from amaranth. It shows a high content of essential amino acids, making this protein important from a nutritional viewpoint. The protein has two disulfide linked subunits: acidic and basic.

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Amarantin acidic subunit has the potential to be employed as a functional and a nutraceutical protein. To evaluate both possibilities this protein was produced in recombinant Escherichia coli Origami (DE3) harboring the expression plasmid pET-AC6His. Three different expression factors were assayed: inductor concentration, temperature and time of the amarantin acidic subunit accumulation.

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The methylotrophic yeast Pichia pastoris was used to express an 11S seed globulin from Amaranthus hypochondriacus. Three different plasmids were tested for expression of amarantin. One of them, which included the untranslated regions (UTR) of the full cDNA, failed to express the amarantin under tested conditions, whereas the other plasmids, one without UTR and the other similar but including the endoplasmic reticulum-retention signal KDEL, were able to express the proamarantin in P.

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Amarantin, an 11S globulin, is one of the most important storage proteins of amaranth seeds, with relevant nutritional-functional and nutraceutical characteristics. Its cDNA was cloned in-frame with a sequence encoding a polyhistidine tag and expressed under the direction of a 35S promoter in transgenic tobacco seeds. The presence of a (His)(6) tag on the polypeptide permitted a high-yield single-step purification using immobilized metal-ion affinity chromatography and rapid characterization.

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Article Synopsis
  • DNA encoding a His-tagged 11S globulin from amaranth was expressed in two E. coli strains, resulting in different protein accumulation patterns; BL21 (DE3) produced mostly inclusion bodies while Origami (DE3) yielded soluble protein (76 mg/L).
  • Soluble proamarantin was found to assemble into trimers, and treatment with an enzyme revealed that it breaks down into acidic and basic chains, indicating proper protein folding similar to that in seeds.
  • The protein was successfully purified using a one-step technique, yielding 48 mg/L, which will help in further studies, including site-directed mutagenesis of this storage protein.
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Prospective testing for allergenicity of proteins obtained from sources with no prior history of causing allergy has been difficult to perform. Thus, the objective of this work was to assess the food safety of genetically modified maize with an amaranth globulin protein termed amarantin. Transgenic maize lines evaluated showed, in relation to nontransgenic, 4-35% more protein and 0-44% higher contents of specific essential amino acids.

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