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1.
Plants (Basel) ; 13(15)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39124250

RESUMO

Sechium edule (Jacq.) Swartz is a perennial herbaceous climbing plant with tendrils and tuberous roots belonging to the Cucurbitaceae family. Its fruits ("chayote"), stems, roots, and leaves are edible and are commonly ingested by humans. It has shown medicinal properties attributed to its bioactive compounds (vitamins, phenolic acids, flavonoids, carotenoids, triterpenoids, polyphenolic compounds, phytosterols, and cucurbitacins), which together have been associated with the control and prevention of chronic and infectious diseases, highlighting its antibacterial, anti-cardiovascular/antihypertensive, antiepileptic, anti-inflammatory, hepatoprotective, antiproliferative, and antioxidant activities. The objective of the study was to determine the antigenotoxic potential of two types of fresh chayote juice (filtered (FChJ) and unfiltered (UFChJ)) against DNA damage produced by benzo[a]pyrene (B[a]P) using an in vivo mouse peripheral blood micronucleus assay (MN). The juices were consumed freely for 2 weeks. A negative control, a control group of each juice, a positive batch [B[a]P], and two combined batches (B[a]P plus FChJ or UFChJ) were included. Blood smears were stained and observed under a microscope to quantify the number of micronucleated normochromic erythrocytes (MNNEs). The results indicate: (a) B[a]P increased the frequency of MNNEs and reduced the rate of PEs; and (b) no juice produced toxic effects or induced MN. On the contrary, both juices were genoprotective. However, the most significant effect was presented by UFChJ at the end of the experiment (70%). It is suggested that UFChJ has a greater amount of fiber and/or phytochemicals that favor the therapeutic effect. Possibly, the genoprotection is also related to its antioxidant capacity.

2.
Foods ; 13(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38672851

RESUMO

Sustainable methods such as convective drying have regained interest in reducing the loss and waste of food produce. Combined with techniques like blanching and edible coatings, they could serve as useful tools in food processing development. Composite coatings comprising pectin, soy protein isolate, and xanthan gum were optimized using response surface methodology with the Box-Behnken design. This optimization aimed to investigate their effects on the moisture content, water activity, total color, and rehydration ratio of fresh and blanched chayote slices. Additionally, the study explored the modeling of the drying kinetics and sorption isotherms of chayote (Sechium edule) slices. Soy protein and xanthan gum were found to primarily influence the moisture content (ranging from 5.44% to 9.93%), and pectin influenced water activity (033 to 0.53) of the fresh-coated chayote, while pectin affected the aw (2.13-8.28) and rehydration of the blanch-coated chayote. The optimized formulations for both fresh and blanched chayote were utilized to assess the drying kinetics behavior and sorption isotherms. The best fit (R2: 0.996 to 0.999) was achieved with the parabolic model for thin-layer materials. Furthermore, the sorption isotherms of chayote displayed a Type IV behavior, with the BET model being the most suitable for describing the sorption behavior of materials with low water activity. The predicted values offer valuable data for optimizing processing conditions to enhance the quality and stability of dried chayote.

3.
Heliyon ; 10(2): e24567, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38312619

RESUMO

Steatosis is characterized by fat accumulation and insulin resistance (IR) in hepatocytes, which triggers a pro-oxidant, pro-inflammatory environment that may eventually lead to cirrhosis or liver carcinoma. This work was aimed to assess the effect of Sechium edule root hydroalcoholic extract (rSe-HA) (rich in cinnamic and coumaric acid, among other phenolic compounds) on triglyceride esterification, lipid degradation, AMPK expression, and the phosphorylation of insulin receptor in a Ser312 residue, as well as on the redox status, malondialdehyde (MDA) production, and the production of proinflammatory cytokines in an in vitro model of steatosis induced by oleic acid, to help develop a phytomedicine that could reverse this pathology. rSe-HA reduced triglyceride levels in hepatocyte lysates, increased lipolysis by activating AMPK at Thr172, and improved the redox status, as evidenced by the concentration of glycerol and formazan, respectively. It also prevented insulin resistance (IR), as measured by glucose consumption and the phosphorylation of the insulin receptor at Ser312. It also prevented TNFα and IL6 production and decreased the levels of MDA and nitric oxide (ON). Our results indicate that rSe-HA reversed steatosis and controlled the proinflammatory and prooxidant environment in oleic acid-induced dysfunctional HepG2 hepatocytes, supporting its potential use to control this disorder.

4.
Methods Mol Biol ; 2759: 97-104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38285143

RESUMO

Chayote (Sechium edule) belongs to the Cucurbitaceae family, an important family at the nutritional and medicinal levels, that has been covering international markets. Having vigorous and healthy plants is important for producers, who are very interested in cultivating chayote plants obtained from in vitro tissue culture in their orchards. Bioreactors have become an alternative with high potential for plant propagation, showing significant advantages over micropropagation in semisolid medium, by generating more plant material, larger, and more vigorous. In this chapter, a micropropagation protocol of S. edule in RITA® bioreactors is reported.


Assuntos
Reatores Biológicos , Cucurbitaceae , Genes de Plantas , Nível de Saúde
5.
Nutrients ; 15(19)2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37836390

RESUMO

The aim was to determine the effect of Sechium edule var. nigrum spinosum (chayote) on gene expression related to antioxidant protection mechanisms and the inflammatory process in older adults with metabolic syndrome (MetS). A quasi-experimental study was carried out in a convenience sample of 46 older adults diagnosed with MetS: (i) placebo group (PG; n = 20); (ii) experimental group (EG; n = 26). The clinical, biochemical, anthropometric parameters and SOD, GPx, and CAT enzyme activity, alongside total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), cytokines (IL-6, IL-8 and TNF-α), and mRNA expression of SOD, GPx, CAT, IL-6, IL-8, TNF-α, Nrf2, NFkB p50, and NFkB p65, were measured at baseline and 6 months post-intervention. A statistically significant decrease was observed in TOS (baseline, 28.9 ± 3.6 vs. post, 23.7 ± 3.4, p < 0.01) and OSI (baseline, 24.1 ± 3.8 vs. post, 17.7 ± 4), as well as an increase in IL-6 (baseline, 10.7 ± 1.1 vs. post, 12.3 ± 2, p = 0.03), SOD activity (baseline, 167.1 ± 11.9 vs. post, 180.6 ± 7.6, p < 0.05), CAT activity (baseline, 1.0 ± 0.2 vs. post, 1.3 ± 0.2, p < 0.01), and TAS (baseline, 1.1 ± 0.1 vs. post, 1.4 ± 0.1, p < 0.01) in the EG compared to the PG. Regarding the expression of Nrf2, SOD, and IL-6, the EG showed a significant increase vs. basal levels (47%, 44%, and 43%, respectively). Our findings suggest that Sechium edule supplementation promotes the antioxidant response and decreases oxidative stress via Nrf2.


Assuntos
Antioxidantes , Síndrome Metabólica , Humanos , Idoso , Antioxidantes/metabolismo , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Suplementos Nutricionais
6.
Redox Rep ; 28(1): 2207323, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37140004

RESUMO

OBJECTIVE: To determine the effect of the consumption of Sechium edule (1.5 g/day) for six months on oxidative stress (OxS) and inflammation markers and its association with telomere length (TL) in older adults with metabolic syndrome (MetS). METHODS: The study was conducted in a sample of 48 older adults: placebo (EP) and experimental (EG) groups. Lipoperoxides, protein carbonylation, 8-OHdG, total oxidant status (TOS), SOD, GPx, H2O2 inhibition, total antioxidant status (TAS), inflammatory cytokines (IL6, IL10, TNF-α), and TL were measured before and six months post-treatment. RESULTS: We found a significant decrease in the levels of lipoperoxides, protein carbonylation, 8-OHdG, TOS in the EG in comparison PG. Likewise, a significante increase of TAS, IL-6, and IL-10 levels was found at six months post-treatment in EG in comparison with PG. TL showed a statistically significant decrease in PG compared to post-treatment EG. CONCLUSIONS: Our findigns showed that the supplementation of Sechium edule has antioxidant, and anti-inflammatory effects, and diminushion of shortening of telomeric DNA in older adults with MetS. This would be the first study that shows that the intervention with Sechium edule has a possible geroprotective effect by preventing telomeres from shortening as usually happens in these patients. Therefore, suggesting a protection of telomeric DNA and genomic DNA.


Assuntos
Antioxidantes , Síndrome Metabólica , Humanos , Idoso , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Síndrome Metabólica/tratamento farmacológico , Peróxidos Lipídicos , Peróxido de Hidrogênio , Telômero/metabolismo
7.
Plants (Basel) ; 12(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36771559

RESUMO

Promoting neglected and underutilized crop species is a possible solution to deal with the complex challenges of global food security. Chayote is a Neglected and Underutilized Cucurbit Species (NUCuS), which is recognized as a fruit vegetable in Latin America and is widely grown in Asia and Africa. However, basic biological knowledge about the crop is insufficient in scientific sources, especially outside of its center of origin. In this study, limited observations on reproductive characters were conducted, differentiating accessions from Mexico, Japan, and Myanmar. Cytological evaluation among Mexican and Japanese accessions showed that the relative nuclear DNA content is 1.55 ± 0.05 pg, the estimated genome size is 1511 at 2C/Mbp, and the observed mitotic chromosomal number is 2n = 28. The genetic diversity of 21 chayote accessions was also examined using six microsatellite markers. A global low genetic heterozygosity (Ho = 0.286 and He = 0.408) and three genetic groups were detected. The results established the basis to provide insights into chayote arrival history in Asia by looking at the crop's reproductive morphology, cytology, and genetic diversity status outside its origin center. This could help in developing sustainable utilization and conservation programs for chayote.

8.
Antioxidants (Basel) ; 11(6)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35739973

RESUMO

Metabolic syndrome (MetS) has a high prevalence in older adults and is a risk factor for cardiovascular diseases and complications of old age. It has also been related to oxidative stress (OxS) and chronic inflammation (CI) and their consequent alterations. Therefore, it is important to propose therapeutic alternatives such as the consumption of Sechium edule (Chayote), since hypoglycemic, hypotensive, and lipogenesis inhibitor properties are attributed to it. We carried out a study in 81 older adults (OA) with MetS to determine the effect of consumption of chayote powder concentrate (500 mg, three times a day) for six months, with a baseline measurement, at three and six months in an experimental group (EG) (n = 41) and a placebo group (PG) (n = 40), all with a diagnosis of MetS according to the criteria of National Adult Treatment Panel of the National Cholesterol Program III (NCEP/ATP III). Anthropometric, biochemical, OxS markers, and inflammation measurements were performed on all participants, basal, three, and six months after. A statistically significant decrease was found in the concentration of lipoperoxides (TBARS), 8-isoprostanes, 8-OHdG, oxidative stress score (OSS), HbA1c, blood pressure, and in the number of MetS diagnostic criteria, as well as an increase in total antioxidant status (TAS), antioxidant gap (GAP), superoxide dismutase (SOD), interleukin 10 (IL-10), and HDL-cholesterol in EG. The results suggest that the consumption of Sechium edule powder has a hypotensive, hypoglycemic, antioxidant, and anti-inflammatory effect in OA with MetS and reduced the percentage of patients with MetS.

9.
Perspect. nutr. hum ; 23(1): 15-26, ene.-jun. 2021. tab
Artigo em Espanhol | LILACS | ID: biblio-1375974

RESUMO

Resumen Antecedentes: la asociación del alto consumo de carnes rojas procesadas con el cáncer colorrectal hace que los consumidores empiecen a demandar productos cárnicos con un perfil nutricional mejorado. Objetivo: diseñar una carne de hamburguesa comercializable, a base de pechuga de pollo, fuente de fibra y baja en grasa con buena aceptación por los consumidores. Materiales y métodos: con base en una formulación estándar de hamburguesa, se hicieron tres formulaciones con adición de fibra como reemplazante de grasa: F1 contenía fibra de cidra (Sechium edule); F2, de zanahoria (Daucus carota); y F3, de inulina. Se calculó la composición nutricional teórica y se realizó una prueba de aceptación por consumidores con una escala de nueve puntos. Resultados: la formulación más aceptada y con mayor contenido de fibra fue la que contenía inulina, con un puntaje de 7,7±1,4 y diferencias significativas, según la prueba T3 de Dunett, con las formulaciones F2 (p=0,001) y F1 (p=0,000), cuyos promedios de aceptación fueron similares: 6,0±2,5 puntos para F2 y 5,9±2,2 para F1 (p=0,931). Las formulaciones con fibra contenían menos grasa y calorías que la formulación control. Conclusión: es posible lograr derivados cárnicos con reducción del contenido de grasa y aporte de fibra sensorialmente aceptados.


Abstract Background: The association between increased consumption of processed red meat and colorectal cancer has driven the demand for meat products with improved nutritional profiles. Objective: To design commercialized hamburger meat that contains chicken breast as the base, fiber, reduced fat, and is accepted by consumers. Materials and Methods: Three formulations were created with a standard hamburger base and additional fiber as a fat replacement: F1 contained fiber from citron (Sechium edule); F2, from carrots (Daucus carota); and F3 from inulin. The theoretical nutritional composition was calculated and a consumer acceptance test was performed on a scale of nine points. Results: The most accepted formulation by consumers with the highest fiber content was the hamburger containing inulin, rated at 7.7±1.4 points. According to the Dunett T3 test, significant differences were reached by F1 (p=0.000) and F2 (p=0.001). They also had similar acceptance averages: F1 (5.9±2.2 points; p=0,000) and F2 (6.0±2.5 points; p=0.001) (p=0.931). The formulations containing added fiber were lowest in fat and calories when compared to the control formulation. Conclusion: It is possible to achieve meat derivatives with reduced fat and added fiber that are sensorily accepted by consumers.


Assuntos
Daucus carota
10.
Antioxidants (Basel) ; 8(5)2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31137783

RESUMO

Metabolic syndrome (MetS) is a risk factor for cognitive deterioration and frailty in older adults. In this regard it has been shown that oxidative stress (OxS) and chronic inflammation are involved in the pathophysiology of these alterations. Harmless antioxidant and anti-inflammatory therapeutic alternatives have been proposed, such as the consumption of Sechium edule (chayote), but the evidence is inconclusive. For this reason, an exploratory study of a single group chosen by convenience sampling, including 12 older adults, with an average age of 71 ± 6 years (10 women and 2 men) with a diagnosis of MetS according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III) criteria. This exploratory study aimed to determine the effect of the consumption of the dried fruit powder supplement of Sechium edule var. nigrum spinosum (500 mg, 3 times per day) for six weeks on the markers of OxS in elderly adults with MetS. All participants' OxS markers were measured before and after treatment. There was a statistically significant decrease in the concentration of lipoperoxides (baseline, 0.289 ± 0.04 vs. post-treatment, 0.234 ± 0.06 µmol/L, p < 0.05), together with a significant increase in total antioxidant status (baseline, 0.97 ± 0.18 vs. post-treatment, 1.2 ± 0.12 mmol/L, p < 0.05). In this sense, the oxidative stress index showed a statistically significant decrease (baseline, 1.7 ± 0.78 vs. post-treatment, 0.75 ± 0.87, p < 0.05). A statistically significant decrease in the concentration of TNF-α after treatment was also found (baseline, 5.3 ± 1.4 vs. post-treatment, 3.5 ± 1.3, p < 0.05).Our findings suggest that the consumption of the dry fruit of Sechium edule has an antioxidant and anti-inflammatory effect in older adults with metabolic syndrome.

11.
Hig. aliment ; 33(288/289): 3365-3369, abr.-maio 2019. tab
Artigo em Português | VETINDEX | ID: biblio-1366305

RESUMO

O estado do Rio de Janeiro apresenta-se como o segundo maior produtor de chuchu do Brasil, sendo produzido, em grande parte, em pequenas propriedades rurais. O chuchu é uma hortaliça fruto, basicamente consumido refogado e em saladas. Nesse contexto, objetivou-se agregar valor ao chuchu e reduzir o seu desperdício, desenvolvendo tecnologias simples e de fácil aplicação para a fabricação de geleias para o pequeno produtor. Os frutos foram adquiridos de produtores locais de Valença-RJ e processados no CEFET, em três formulações, com diferentes concentrações de chuchu e de morango. As análises físico-químicas realizadas foram as de cinzas, proteínas, acidez total titulável, pH, sólidos solúveis, SST/ATT, atividade de água e açúcares redutores. As análises microbiológicas realizadas foram para bolores e leveduras. Conclui-se que as três formulações de geleias apresentaram características físico-químicas e microbiológicas dentro dos padrões estabelecidos pela legislação vigente do país.


Assuntos
Técnicas Microbiológicas , Fragaria , Alimentos Industrializados , Geleia de Frutas , Fenômenos Químicos
12.
Int J Biol Macromol ; 127: 502-510, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30658148

RESUMO

The contribution of dietary fiber to decrease the risk of atherosclerosis may occur through other mechanisms besides the increased excretion of cholesterol. Although macrophages are crucial for lipid clearance, the excessive uptake of cholesterol crystals (CC) by these cells induce NLRP3 inflammasome and foam cell formation. Thus, we investigated whether the water-soluble DF from chayote (WSP) regulate CC-pretreated macrophage-like THP-1 cells. Linkage analysis indicated that WSP is composed mainly of pectic homogalacturonan and highly branched type I rhamnogalacturonan as well as hemicellulosic material including glucomannan, xyloglucan, and glucurono(arabino)xylan. WSP reduced interleukin (IL)-1ß and chemokine release in CC-pretreated macrophages. Notably, WSP also reduced lipid accumulation in cells previously exposed to CC. Furthermore, WSP upregulated liver X receptor alpha expression, which may account for increased lipid efflux, and reduced matrix metallopeptidase 9 expression. WSP also reduced active caspase-1 protein levels, and downregulated NLRP3 and IL-1ß gene expression in CC-pretreated cells, suggesting that this polysaccharide fraction regulates the priming signals required for NLRP3 inflammasome activation. Thus, WSP regulate lipid efflux and suppress inflammasome priming in macrophages, suggesting that the health benefits of this dietary fiber could go beyond its physical properties on the gastrointestinal tract.


Assuntos
Colesterol/farmacologia , Cucurbitaceae/química , Células Espumosas/metabolismo , Inflamassomos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Polissacarídeos/farmacologia , Humanos , Polissacarídeos/química , Células THP-1
13.
J Ethnopharmacol ; 220: 75-86, 2018 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-29501845

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: A recent ethnomedical survey on medicinal plants grown in Mexico revealed that Sechium edule (Jacq.) Sw. (Cucurbitaceae) is one of the most valued plant species to treat cardiovascular diseases, including hypertension. Fruits, young leaves, buds, stems, and tuberous roots of the plant are edible. Considering that endothelial dysfunction induced by Angiotensin II plays an important role in the pathogenesis of hypertension and is accompanied by a prooxidative condition, which in turn induces an inflammatory state, vascular remodeling, and tissue damage, and that S. edule has been reported to possess antioxidant, anti-inflammatory and antihypertensive activity, its capability to control endothelial dysfunction was also assessed. AIM OF THE STUDY: To assess in vivo the anti-endothelial dysfunction activity of the acetone fraction (rSe-ACE) of the hydroalcoholic extract from S. edule roots. MATERIALS AND METHODS: Endothelial dysfunction was induced in female C57BL/6 J mice by a daily intraperitoneal injection of angiotensin II for 10 weeks. Either rSe-ACE or losartan (as a control) were co-administered with angiotensin II for the same period. Blood pressure was measured at weeks 0, 5, and 10. Kidney extracts were prepared to determine IL1ß, IL4, IL6, IL10, IL17, IFNγ, TNFα, and TGFß levels by ELISA, along with the prooxidative status as assessed by the activity of antioxidant enzymes. The expression of ICAM-1 was evaluated by immunohistochemistry in kidney histological sections. Kidney and hepatic damage, as well as vascular tissue remodeling, were studied. RESULTS: The rSe-ACE fraction administered at a dose of 10 mg/kg was able to control hypertension, as well as the prooxidative and proinflammatory status in kidney as efficiently as losartan, returning mice to normotensive levels. Additionally, the fraction was more efficient than losartan to prevent liver and kidney damage. Phytochemical characterization identified cinnamic acid as a major compound, and linoleic, palmitic, and myristic acids as the most abundant non-polar components in the mixture, previously reported to aid in the control of hypertension, inflammation, and oxidative stress, three important components of endothelial dysfunction. IN CONCLUSION: this study demonstrated that rSe-ACE has anti-endothelial dysfunction activity in an experimental model and highlights the role of cinnamic acid and fatty acids in the observed effects.


Assuntos
Cucurbitaceae/química , Endotélio Vascular/efeitos dos fármacos , Extratos Vegetais/farmacologia , Doenças Vasculares/prevenção & controle , Acetona/química , Angiotensina II/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Antioxidantes/metabolismo , Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Modelos Animais de Doenças , Endotélio Vascular/patologia , Ácidos Graxos/isolamento & purificação , Ácidos Graxos/farmacologia , Feminino , Losartan/farmacologia , México , Camundongos , Camundongos Endogâmicos C57BL , Raízes de Plantas , Doenças Vasculares/patologia
14.
Curr Pharm Des ; 24(40): 4807-4824, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30644341

RESUMO

BACKGROUND: Oxidative stress (OxS) is a biochemical process characterized by an imbalance between the production of reactive species (RS) and antioxidants in favor of the former that subsequently induces the oxidative damage of biomolecules and alters cellular physiology. OxS exerts diverse effects and is associated with the pathophysiology of more than 100 diseases, as well as with the aging process. OxS also plays a role in maintaining the homeostasis of both animal and plant organisms. We analyze the role and mechanisms of the generation of RS and antioxidants both under physiological conditions and during aging and pathological processes. Likewise, the potential of antioxidant agents from the diet is considered, specifically fruits such as chayote. We focus on naringenin, a flavonoid with a high antioxidant capacity. METHOD: We conducted a literature review to present the state of the art of knowledge about the biological significance of oxidative stress and the effect of antioxidants in some edible fruits. CONCLUSIONS: Evidence supports the existence of RS, their physiological roles as well its harmful effects when oxidative stress occurs. In this sense, given the association of oxidative stress with diseases and aging the fruits rich in antioxidants are a feasible alternative to restore de redox balance if necessary.


Assuntos
Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Frutas/química , Estresse Oxidativo/efeitos dos fármacos , Plantas Comestíveis/química , Animais , Humanos
15.
Molecules ; 20(10): 19372-92, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26512637

RESUMO

ß-Glucosidase (EC 3.2.1.21) is a prominent member of the GH1 family of glycoside hydrolases. The properties of this ß-glucosidase appear to include resistance to temperature, urea, and iodoacetamide, and it is activated by 2-ME, similar to other members. ß-Glucosidase from chayote (Sechium edule) was purified by ionic-interchange chromatography and molecular exclusion chromatography. Peptides detected by LC-ESI-MS/MS were compared with other ß-glucosidases using the BLAST program. This enzyme is a 116 kDa protein composed of two sub-units of 58 kDa and shows homology with Cucumis sativus ß-glucosidase (NCBI reference sequence XP_004154617.1), in which seven peptides were found with relative masses ranging from 874.3643 to 1587.8297. The stability of ß-glucosidase depends on an initial concentration of 0.2 mg/mL of protein at pH 5.0 which decreases by 33% in a period of 30 h, and then stabilizes and is active for the next 5 days (pH 4.0 gives similar results). One hundred µg/mL ß-D-glucose inhibited ß-glucosidase activity by more than 50%. The enzyme had a Km of 4.88 mM with p-NPG and a Kcat of 10,000 min(-1). The optimal conditions for the enzyme require a pH of 4.0 and a temperature of 50 °C.


Assuntos
Cucurbitaceae/enzimologia , beta-Glucosidase/isolamento & purificação , Sequência de Aminoácidos , Precipitação Química , Cromatografia por Troca Iônica , Estabilidade Enzimática , Glucose/química , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Proteínas de Plantas , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , beta-Glucosidase/química
16.
Ciênc. agrotec., (Impr.) ; 34(1): 182-189, jan.-fev. 2010. ilus
Artigo em Português | LILACS | ID: lil-541470

RESUMO

Objetivou-se avaliar o efeito do tempo de armazenamento sobre a qualidade de produto minimamente processado à base de hortaliças: abóbora (Cucurbita moschata Duch), cenoura (Daucus carota L.), chuchu (Sechium edule Swartz) e mandioquinha-salsa (Arracacia xanthorrhiza Bancroft). As hortaliças foram sanificadas em hipoclorito de sódio 200 mg.L-1, por 5 minutos, descascadas, manualmente, e cortadas utilizando-se processador. O produto processado foi sanificado em hipoclorito de sódio 50 mg.L-1, por 3 minutos, e apenas as mandioquinhas-salsa foram imersas em solução de ácido ascórbico 1 por cento, por 2 minutos. As embalagens flexíveis de polietileno de baixa densidade linear (25 x 20 cm), contendo 400 g do "mix", foram armazenadas a 5ºC e 99 por cento UR, por 8 dias. A firmeza e o valor L* das hortaliças estudadas não alteraram com o tempo de armazenamento. Os valores a* e b* da abóbora não oscilaram durante o armazenamento. O valor a* da mandioquinha-salsa e do chuchu aumentou e o da cenoura diminuiu com o armazenamento, enquanto o valor b* da cenoura, do chuchu e da mandioquinha-salsa reduziu. O "mix" apresentou taxa de perda de massa muito baixa e ascensão respiratória até o oitavo dia. A atmosfera de equilíbrio, em torno de 2,93 por cento de O2 e 7,06 por cento de CO2, foi alcançada no interior da embalagem, contendo o "mix", a partir do segundo dia. Não foi detectada a presença de coliformes a 45ºC e Salmonella sp. em nenhuma amostra. Os coliformes a 35ºC aumentaram durante o armazenamento. Conclui-se que, o produto minimamente processado, à base de hortaliças mantém a sua qualidade por 8 dias a 5ºC.


The objective of this work was to evaluate the effect of storage time on the quality of fresh-cut product made up of four vegetables: pumpkin (Cucurbita moschata Duch), carrot (Daucus carota L.), chayote (Sechium edule Swartz), and peruvian carrot (Arracaia xanthorrhiza Bancroft). The vegetables were sanitized in sodium hypochlorite solution (200 mg.L-1) for 5 minutes, manually peeled, and then cut by using a processor. The processed product was sanitized in sodium hypochlorite solution (50 mg.L-1) for 3 minutes; and only the peruvian carrot was immersed in solution of ascorbic acid (1 percent) for 2 minutes. The flexible packages of low-density polyethylene (25 x 20 cm), containing 400 g of the mix, were stored at 5ºC and RH 99 percent, for 8 days. The firmness and the L* value of the studied vegetables did not change during the storage time. The a* and b* values of the pumpkin did not oscillate during storage. The a* value of the peruvian carrot and the chayote increased. But the carrot value decreased during the storage period. The b* value of the carrot, chayote, and the peruvian carrot decreased during storage. The mix presented a very low rate of mass loss and respiratory ascension to the eighth day. The steady state atmosphere, around 2,93 percent of O2 and 7.06 percent of CO2, was reached in the package containing the "mix", from the second day. Presence of coliforms at 45ºC and Salmonella sp. was not detected in any sample. During the storage period at 35ºC, coliform count increased. It was concluded that fresh-cut product made up of vegetables keeps its quality for 8 days at 5ºC.

17.
Neotrop. entomol ; 30(3): 475-477, Sept. 2001. ilus
Artigo em Português | LILACS | ID: lil-514385

RESUMO

The simultaneous occurrence of Adetus analis (Haldeman), Adetus fuscoapicalis Breuning and Plerodia syrinx (Bates) (Coleoptera: Cerambycidae, Lamiinae) is reported boring the stems of chayote, Sechium edule. A. analis is the same species as Adetus muticus (Thomson) been wich was referred before by several authors in Brazil. A. analis and A. fuscoapicalis are similar in morphologic and ethologic aspects. This paper presents a detailed description and illustrations of both species in order to help in the identification of these species. P. syrinx, which shows the same attacking behavior of these species of Adetus, also had its morphological characters described, in pupal and adult stages.


A ocorrência simultânea de Adetus analis (Haldeman), Adetus fuscoapicalis Breuning e Plerodia syrinx (Bates) (Coleoptera: Cerambycidae, Lamiinae), broqueando ramos de chuchuzeiro Sechium edule (Jaqc.) Sw., é relatada. A. analis é sinônima de A. muticus (Thomson), que foi referida por diversos autores no Brasil. A. analis e A. fuscoapicalis são muito semelhantes quanto aos aspectos morfológicos e etológicos. Assim foi realizada uma descrição detalhada e ilustrações de ambas espécies a fim de promover uma identificação segura. P. syrinx, que apresenta comportamento de ataque semelhante ao das espécies de Adetus, também foi descrita em seus caracteres morfológicos nas fases de pupa e adulto.

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