Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
J Mol Graph Model ; 122: 108502, 2023 07.
Article in English | MEDLINE | ID: mdl-37116336

ABSTRACT

Polygalacturonase (PG) is an important hydrolytic enzyme involved in pectin disassembly and the subsequent textural changes during fruit ripening. Although the interaction of fungal PGs with other proteins has been documented, the interaction of plant PGs with other plant proteins has not yet been studied. In this study, the molecular mechanisms involved in raspberry fruit ripening, particularly the polygalacturonase (RiPG) interaction with polygalacturonase inhibiting protein (RiPGIP) and substrate, were investigated with a structural approach. The 3D model of RiPG2 and RiPGIP3 was built using a comparative modeling strategy and validated using molecular dynamics (MD) simulations. The RiPG2 model structure comprises 11 complete coils of right-handed parallel ß-helix architecture, with an average of 27 amino acid residues per turn. The structural model of the RiPGIP3 displays a typical structure of LRR protein, with the right-handed superhelical fold with an extended parallel ß-sheet. The conformational interaction between the RiPG2 protein and RiPGIP3 showed that RiPGIP3 could bind to the enzyme and thereby leave the active site cleft accessible to the substrate. All this evidence indicates that RiPG2 enzyme could interact with RiPGIP3 protein. It can be a helpful model for evaluating protein-protein interaction as a potential regulator mechanism of hydrolase activity during pectin disassembly in fruit ripening.


Subject(s)
Polygalacturonase , Rubus , Polygalacturonase/chemistry , Polygalacturonase/metabolism , Rubus/metabolism , Molecular Dynamics Simulation , Fruit/metabolism , Pectins/metabolism , Plant Proteins/metabolism
2.
Foods ; 10(1)2020 Dec 25.
Article in English | MEDLINE | ID: mdl-33375582

ABSTRACT

Crystalline material can develop on the surface of raisins during storage and transport, affecting the final acceptability of the product. In this work, a mild thermal pretreatment was applied to raisins to melt the pre-existing crystals and the effect of such thermal treatments on the development of crystals over a storage period was investigated. The raisins selected for this study were of the Thompson seedless variety from one Chilean company. The thermal pretreatment of raisins at 50 °C and 70 °C for 20 min in an oven and microwave (800 W) irradiation for 15 s resulted in a reduction in the percentage of crystallized raisins (w/w) from more than 50% in the control samples to less than 10% after 35 days of storage at 15 and 25 °C in a 57% relative humidity environment. The results showed that some textural parameters, such as cohesiveness and chewiness, were not affected by thermal treatment and were independent of storage temperature.

3.
Data Brief ; 31: 105986, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32695856

ABSTRACT

The current data presented correspond to the determination of inulin recovery from globe artichoke canned industry wastes. The discard was composed mainly by bracts with a small percentage of stems and receptacles. Artichoke discards (AD) were dehydrated by lyophilization or convective drying at different temperatures (40°C to 100°C). Inulin amount in extracts obtained using hydroalcoholic solvents (ethanol:water 75:25), which are applied for polyphenols recovery, was determined. After that, the sequential extraction of inulin with water and then with hydroalcoholic solvent was done. Finally, inulin content in lyophilized samples using different ethanol:water mixtures was determined. Inulin was determined by vanillin method and total phenolic compounds (TPC) by Folin-Ciocalteu method. From the lyophilized sample it is possible to obtain 3938.7 ± 169.1 mg inulin / 100 g AD dry basis (d.b.) and 2086.3 ± 120.7 mg TPC / 100 g AD d.b. While, from conventionally dried samples, the recovery of inulin can reach 4391.1 ± 208.2 mg inulin / 100 g AD d.b for samples dried at 60°C, but only 337.2 ± 25.9 mg TPC / 100 g AD d.b. was recovered at the same condition. Sequential extraction of lyophilized samples with water (95°C, 30 minutes) and ethanol:water 75:25 (40°C, 60 minutes) recovers in total 10907.3 mg inulin / 100 g AD and 2687.7 mg TPC / 100 g AD d.b. If the ethanol concentration decreases at 50% and the extraction is done only with the hydroalcoholic solvent, the inulin increases up to 5251.2 ± 257.4 mg inulin / 100 g AD d.b. This Data in Brief corresponds to an accompanying work to the article titled "Valorization of Globe Artichoke (Cynara scolymus) Agro-Industrial Discards, Obtaining an Extract with a Selective Effect on Viability of Cancer Cell Lines" published at Processes journal [1].

4.
Food Chem ; 317: 126381, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32097821

ABSTRACT

After prolonged storage or during the shipment of raisins, a crystalline material may be developed on their surface, affecting the final acceptability of the product. The mild thermal pretreatment (50 °C for a period of 12 h and 48 h) was applied to dissolve any potential tiny crystals and nuclei already present in the raisins. The thermal pretreatment of raisins resulted in a reduction on the percentage of crystallized raisins (w/w) from more than 46% in control samples to less than 10% after 30 days of storage at 57% and 66% of relative humidity and 15 °C and 25 °C. X-ray diffraction analysis identified d-Glucose monohydrate as the main crystalline component. All the thermal treatments increased the hardness of the raisins, when they were incubated at 57% relative humidity. To mitigate the problems of crystallization of raisins during shipping, it is recommended that the raisins are thermally pretreated and the shipping conditions are controlled.


Subject(s)
Food Storage , Hot Temperature , Humidity , Sugars/chemistry , Vitis/chemistry , Chemical Phenomena , Color , Crystallization , Glucose/chemistry , Hydrogen-Ion Concentration , Kinetics , X-Ray Diffraction
5.
Data Brief ; 27: 104735, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31763393

ABSTRACT

Probiotics must be delivered alive to exert a positive health effects in site of action. But, they must survive different extreme condition through intestinal tract. Microencapsulation techniques have received considerable attention and facilitate a suitable carrier system to reach the target site. The encapsulation techniques applied to probiotics can be classified into two groups, depending on the method used to form the beads: extrusion (droplet method) and emulsion or two-phase system [1], where extrusion is evolved in the vibration technology and in particular, when the wavelength of an asymmetric disturbance exceeds the jet circumference, the break-up occurs. Droplet size depends on nozzle (jet) diameter, viscosity of fluid, surface tension, jet velocity and frequency of disturbance [2,3]. The data presented in this article evaluated the performance of microencapsulated Lactobacillus casei (probiotic bacteria) using vibration technology and using two kinds of sodium alginate gel matrix (low and medium viscosity) and compare the effect over viability. The best conditions for higher viability of probiotics were at a concentration of sodium alginate (medium viscosity) at 2%, with a nozzle of 450 µm and a frequency of 1000 Hz. The data are related to the research article entitled "Microencapsulation of probiotics by efficient vibration technology" [3], where Microencapsulator provide by BÜCHI (Encapsulated B-390) was used.

6.
Electron. j. biotechnol ; 42: 42-48, Nov. 2019. graf, tab, ilus
Article in English | LILACS | ID: biblio-1087459

ABSTRACT

Background: Foods including probiotics are considered "functional foods." As an alternative to dairy products, we investigated the behavior of Lactobacillus casei when exposed to low-pH fruit juice. Juices of fruits such as pineapple, raspberry, and orange were assessed. Free and microencapsulated forms of L. casei were compared, and the viability of the probiotic was evaluated under storage at 4°C for 28 d. Microbiological analyses were carried out to ensure a safe and healthy product for consumers who look for foods with probiotics from sources other than dairy. Results: Low pH affected L. casei survival during storage depending on the type of fruit juice. In the case of pineapple juice, some microcapsules were broken, but microcapsules recovered at the end of the storage period had 100% viability (2.3 × 107 CFU/g spheres). In the case of orange juice, more than 91% viability (5.5 × 106 CFU/g spheres) was found. In raspberry juice, viability decreased rapidly, disappearing at the end of the storage period, which was caused by the absorption of high concentrations of anthocyanin inside microcapsules more than low pH. Conclusion: Low pH affected the survival of L. casei under refrigeration; even when they were microencapsulated, acidic conditions impacted their viability. Although pH affects viability, its value is very sensitive and will depend on the type of fruit juice and its composition. Some fruit juices contain compounds used as substrates for Lactobacillus and other compounds with antimicrobial effects.


Subject(s)
Microbial Viability , Fruit and Vegetable Juices , Lacticaseibacillus casei/growth & development , Vibration , Cold Temperature , Probiotics , Alginates/chemistry , Food Storage , Pasteurization , Hydrogen-Ion Concentration , Anthocyanins
7.
J Microencapsul ; 34(7): 667-674, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28985684

ABSTRACT

The target site of action of probiotics is the intestine. They must be surviving the stomach acidic condition before reaching the target site. Three probiotic bacteria were microencapsulated in sodium alginate beads using a sophisticated microencapsulation technology provided by BÜCHI B-390. This study reports the tolerance of the different microencapsulated Lactobacillus at low pH using simulated gastric juice, comparing it with the tolerance of free bacteria. The three microencapsulated strains displayed time-dependent acid sensitivity at pH values under 3.0. At pH 2.0, a dramatic reduction in bacterial survival occurred after 5 min, with only L. casei surviving after 30 min, with 75% survival. At pH 2.5 microencapsulated L. casei survived for 90 , L. reuteri survived for 60 and L. bulgaricus survived for only 30 min, respectively. The microencapsulation technology used in this study may effectively protect Lactobacillus from gastric conditions and permit comparisons between strains.


Subject(s)
Drug Compounding , Probiotics , Hydrogen-Ion Concentration , Lactobacillus/metabolism , Vibration
8.
Electron. j. biotechnol ; 18(4): 291-294, July 2015. ilus, graf
Article in English | LILACS | ID: lil-757866

ABSTRACT

Background Polycosanols derived from plant species have traditionally been used in medicine as antiproliferative agents for treating various viruses (primarily the herpes simplex virus). However, few studies have studied their effects on hyperproliferative cell lines. In this work, the antiproliferative capacity of polycosanols from tall-oil pitch, obtained from black liquor soaps in the kraft pulping process of cellulose (specifically from Pinus radiata, Pinus taede, and Eucalyptus globulus), was evaluated on CHO-K1 and CRL-1974 human melanoma cell lines. Results The proliferative capacities and cell viabilities were measured for 72 and 140 h, respectively. Treatment with docosanol produced differential effects on the CHO-K1 and human melanoma cells and significantly affected their proliferation rates, but not their cell viabilities. Tetracosanol produced a significant negative effect on the proliferation of human melanoma cells, and this effect was less than that caused by docosanol. However, it had no effect on the proliferation of CHO-K1 cells and did not induce any significant effect on the viability of the studied cell lines. Conclusion Docosanol and tetracosanol induced antiproliferative effects on the studied cell lines and exhibited significantly greater effects on the oncogenic cell lines. Prior to this study, the capacity of these polycosanols has never been investigated. Future studies will be necessary to determine their mechanisms of action on these cell systems.


Subject(s)
Humans , Plant Oils , Cell Proliferation/drug effects , Fatty Alcohols/pharmacology , Fatty Alcohols/chemistry , Melanoma , CHO Cells , Pinus , Cell Line, Tumor , Eucalyptus
9.
Oncol Rep ; 33(5): 2235-44, 2015 May.
Article in English | MEDLINE | ID: mdl-25778435

ABSTRACT

Mammary cancer is the most frequent type of tumor in the female canine. Treatments are mainly limited to surgery and chemotherapy; however, these tumors may develop clinical recurrence, metastasis and chemoresistance. The existence of a subpopulation of cancer cells with stemness features called cancer stem-like cells, may explain in part these characteristics of tumor progression. The statins, potent blockers of cholesterol synthesis, have also shown antitumor effects on cancer mammary cells, changes mediated by a decrease in the isoprenylation of specific proteins. Few studies have shown that simvastatin, a lipophilic statin, sensitizes cancer stem-like cells eliminating drug resistance. The aim of the present study was to evaluate the effects of simvastatin on spheres derived from CF41.Mg canine mammary tumor cells, which were characterized by phenotypic and functional analyses. Spheres exhibited characteristics of stemness, primarily expressing a CD44⁺/CD24⁻/low phenotype, displaying auto-renewal and relative chemoresistance. Exposure to simvastatin induced a decrease in the sphere-forming capacity and cell viability, accompanied by a concentration- and time-dependent increase in caspase-3/7 activity. In addition, modulation of ß-catenin and p53 expression was observed. Simvastatin triggered a synergistic effect with doxorubicin, sensitizing the spheres to the cytotoxic effect exerted by the drug. Invasiveness of spheres was decreased in response to simvastatin and this effect was counteracted by the presence of geranylgeranyl pyrophosphate. Our results suggest that simvastatin targets canine mammary cancer stem-like cells, supporting its therapeutical application as a novel agent to treat canine mammary cancer.


Subject(s)
Antineoplastic Agents/pharmacology , Dog Diseases/pathology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Mammary Neoplasms, Animal/pathology , Neoplastic Stem Cells/drug effects , Simvastatin/pharmacology , Animals , Blotting, Western , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dogs , Female , Flow Cytometry , Immunohistochemistry , In Situ Nick-End Labeling , In Vitro Techniques , Spheroids, Cellular/drug effects
10.
PLoS One ; 9(9): e107749, 2014.
Article in English | MEDLINE | ID: mdl-25248107

ABSTRACT

Structured Lipids are generally constituents of functional foods. Growing demands for SL are based on a fuller understanding of nutritional requirements, lipid metabolism, and improved methods to produce them. Specifically, this work was aimed to add value to avocado oil by producing dietary triacylglycerols (TAG) containing medium-chain fatty acids (M) at positions sn-1,3 and long-chain fatty acids (L) at position sn-2. These MLM-type structured lipids (SL) were produced by interesterification of caprylic acid (CA) (C8:0) and avocado oil (content of C18:1). The regiospecific sn-1,3 commercial lipases Lipozyme RM IM and TL IM were used as biocatalysts to probe the potential of avocado oil to produce SL. Reactions were performed at 30-50°C for 24 h in solvent-free media with a substrate molar ratio of 1∶2 (TAG:CA) and 4-10% w/w enzyme content. The lowest incorporation of CA (1.1% mol) resulted from Lipozyme RM IM that was incubated at 50°C. The maximum incorporation of CA into sn-1,3 positions of TAG was 29.2% mol. This result was obtained at 30°C with 10% w/w Lipozyme TL IM, which is the highest values obtained in solvent-free medium until now for structured lipids of low-calories. This strategy opens a new market to added value products based on avocado oil.


Subject(s)
Lipase/metabolism , Persea/chemistry , Plant Oils/chemistry , Triglycerides/metabolism , Biocatalysis , Caprylates/metabolism , Dietary Fats/metabolism , Enzymes, Immobilized/metabolism , Esterification , Plant Oils/metabolism , Triglycerides/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...