Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Crit Rev Food Sci Nutr ; 63(19): 3980-3993, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34702104

RESUMO

Autism spectrum disorders (ASD) are defined as neurodevelopmental disorders, which are highly variable in nature and do not form a uniform picture, either in terms of symptomatology or depth of the disturbance. Diagnosis of ASD is made for children who show signs of impairment in social interaction, communication and cognitive skills. The exact cause of autism spectrum disorders has not been determined to date. Although there is no cure for ASD, a variety interventions have been proposed. The most commonly used restrictive dietary intervention is the gluten-free casein-free diet (GFCF), which is based on the opioid excess theory. This paper summarizes and discusses research on the core elements of the opioid excess theory in ASD: increased levels of opioid peptides in body fluids in ASD patients, increased intestinal permeability, altered peptidase activity and the effectiveness of GFCF diet in alleviating symptoms of ASD. Furthermore, we discuss the difficulties and their causes in conducting research with ASD patients. The assumptions of the opioid excess theory have neither been definitively confirmed nor disproved. Research in this area should continue, taking into account the highest possible quality standards and the specific needs and abilities of patients with ASD and their families.


Assuntos
Transtorno do Espectro Autista , Criança , Humanos , Analgésicos Opioides/efeitos adversos , Dieta Livre de Glúten , Caseínas
2.
Rocz Panstw Zakl Hig ; 71(3): 321-328, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32938324

RESUMO

Background: Gluten-free and casein-free diet is frequently used in the support of therapy of children with autism spectrum disorders. In addition, many parents restrict the consumption of simple sugars for their children. Objective: The aim of this paper was to understand factors influencing purchase decision in case of family with children with autism spectrum disorders on gluten-free and/or casein-free and/or sugar-free diet and the difficulties associated with this type of nutrition. Material and methods: The study covered a group of 40 families with children with autism spectrum disorders (32 boys and 8 girls) aged 3 to 10 years. Data were collected with questionnaire included questions concerning overall characteristics of caregivers, availability of foods used in the special diet, factors affecting decision on the purchase of products, difficulties in maintaining the child nutrition method. Results: The factors having strongest impact on parents' decisions on the purchase of products were product composition, presence of a certificate confirming the absence of gluten and/or milk and taste values. Exclusion diet constituted a considerable obstruction for traveling, social gatherings and resulted in conflicts with family and the environment. The limited range of healthy gluten-free, casein-free and sugar-free foods, low taste quality and unsatisfactory quality impeded purchase and preparation of varied meals. Conclusions: The surveyed parents were aware consumers, paying attention primarily to product composition and safety. The respondents were looking for healthy, organic and nutritionally valuable products with low sugar content. Further development of the gluten/casein/ sugar free products market may considerably improve certain aspects of family's life with children with autism spectrum disorders.


Assuntos
Transtorno do Espectro Autista/dietoterapia , Comportamento do Consumidor/economia , Dietoterapia/economia , Dietoterapia/psicologia , Dieta Livre de Glúten/economia , Dieta Livre de Glúten/psicologia , Pais/psicologia , Adulto , Animais , Caseínas/efeitos adversos , Criança , Pré-Escolar , Tomada de Decisões , Dieta com Restrição de Proteínas , Feminino , Humanos , Masculino , Açúcares/efeitos adversos , Inquéritos e Questionários
3.
J Food Sci Technol ; 56(5): 2628-2638, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31168145

RESUMO

Oxidative stability of lipid fractions extracted from sponge-fat cakes enriched with green tea extracts and synthetic antioxidant (BHA) directly after baking and after 28 days of storage was investigated. This was achieved by the determination of peroxide (PV), p-anisidine (p-AnV) and acid values (AV), and using Rancimat test or differential scanning calorimetry method, respectively. The results showed that the lipid fractions extracted from sponge-fat cakes containing the addition of BHA (0.02%) and green tea extract at concentrations of 1% exhibited a greater resistance to oxidation than those from cakes without additives. AV values were the lowest for lipids extracted from sponge-fat cakes enriched with 1% green tea extract up to the end of storage. The incorporation of BHA and green tea extract (1%) into cakes caused a gradual increase of PV and p-AnV values during 21 days of sample storage. The values of these parameters increased significantly for samples without any additives, especially in regard to PV. What is more, thermal analysis showed that samples enriched with 1% green tea extract and with BHA were characterized by higher onset temperature (tON), activation energy, and induction time (τ) than samples without any additives, especially during 21 days of storage. The increase of green tea extract concentration to 1% in cookies reduced L* (from 63.85 to 51.15) and b* (from 34.64 to 29.11) values, while a* value showed an increase from 8.43 to 11.17.

4.
Chem Zvesti ; 72(10): 2607-2615, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30147227

RESUMO

The present study was conducted to determine and compare the oxidative stability of soybean and sunflower oils using differential scanning calorimetry (DSC). These edible oils were enriched with marjoram (Origanum majorana L.), thyme (Thymus vulgaris L.), and oregano (Origanum vulgare L.) extracts at three different concentrations and synthetic antioxidant (BHA). The fatty acid composition of studied oils was determined by gas chromatography mass spectrometry to evaluate the content of unsaturated fatty acids that are sensitive to oxidation process. Oil samples were heated in the DSC at different heating rates (4.0, 7.5, 10.0, 12.5, and 15.0 °C min-1) and oxidation kinetic parameters (activation energy, pre-exponential factor, and oxidation rate constant) were calculated. The results showed that the oxidative stability of sunflower oil samples enriched with oregano extracts and soybean oil supplemented with thyme extracts was improved compared to samples without the addition of herbal plant extracts and the synthetic antioxidant.

5.
Rocz Panstw Zakl Hig ; 69(2): 111-118, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29766689

RESUMO

Coffee is the most popular hot beverage in the world. The annual coffee production in 2010, 2014 and 2016 was 8.1, 9.0 and 9.3 million tons respectively. There are more than 100 coffee species, but only two of them: Arabica (Coffea arabica) and Robusta (Coffea canephora) have gained commercial importance. During roasting of green coffee beans not only desirable compounds are formed, that exert positive influence on the taste and flavour of coffee, but also small quantities of undesirable ones. Furan (C4H4O) is one of the latter. Furan is a volatile compound (boiling temp. of 31.4 oC) formed during thermal processing of food. The toxicity of furan has been well documented and it is classified as "possible human carcinogen" (Group 2B) by the International Agency for Research on Cancer. Various pathways have been reported for furan formation during food processing. It can be formed from carbohydrates, amino acids by their thermal degradation or thermal re-arrangement and by oxidation of ascorbic acid and polyunsaturated acids and carotenoids. High concentrations of furan have been reported in coffee, baked and roasted food and in food subjected to preserving in cans and jars. Furan levels in brewed coffee are typically near or below 120 µg/L, but it can approach thousands µg/kg in roasted whole beans or ground coffee. The highest concentration of furan in roasted coffee reaches the level of 7000 µg/kg. Taking into account that coffee is the most popular hot drink, it becomes the main contributor to furan exposure from dietary sources for adults. In this article the published scientific papers concerned with the presence of furan in roasted non-brewed and brewed coffee have been reviewed. The formation mechanisms and occurrence of furan in coffee and the harmful influence of furan on the consumer health have been discussed.


Assuntos
Coffea/química , Café/química , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Furanos/efeitos adversos , Sementes/química , Humanos
6.
J Am Oil Chem Soc ; 94(5): 661-671, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28479605

RESUMO

This study was aimed at evaluating the capability of Yarrowia lipolytica W29 for the synthesis of lipolytic enzymes in a medium containing plant oils from non-conventional sources with some components displaying bioactivity. Oils from almond, hazelnut, and coriander seeds were obtained by using n-hexane (Soxhlet method) and a chloroform/methanol mixture of solvents (Folch method), and their effect on the growth and lipolytic activity of Y. lipolytica was compared. A comparison of these two extraction methods showed that the extraction with n-hexane was less effective regarding the oil extraction yields than the extraction conducted according to Folch's procedure. The lipolytic activity of the studied yeast was higher in the culture media containing oils extracted with the Soxhlet method than the Folch method but it was lower compared to olive oil medium. Among all oils tested, almond oil extracted with n-hexane was the best inducer of extracellular lipases synthesized by Y. lipolytica. Its lipolytic activity achieved the maximum value of 2.33 U/mL after 48 h of culture. After 24 h of culture, it was close to the value obtained for the medium containing olive oil. Almond oil was a source of oleic and linoleic acids, which may determine differences in the lipolytic activity. The linoleic acid content in almond oil was higher than that found in other oils. When n-hexane was used for extraction, the resultant oils were characterized by lower contents of polyphenols and poorer antioxidative activity.

7.
Acta Pol Pharm ; 72(4): 757-67, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26647633

RESUMO

Chemical composition and antibacterial activity of aqueous (ethanolic and methanolic) extracts from herbs often used in Polish cuisine and traditional herbal medicine including thyme (Thymus vulgaris L.), rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.), peppermint (Mentha piperita L.) and sage (Salvia officinalis L.) were compared. The aqueous ethanolic extracts contained slightly higher levels of phenolics compared to the aqueous methanolic extracts. In turn, GC-MS analysis showed that the aqueous methanolic extracts of thyme, rosemary and sage contained several additional compounds such as eugenol or ledol. The present studies also indicated that the bacterial species applied in the experiment exhibited different sensitivities towards tested extracts. Staphylococcus aureus strains were found to be the most sensitive bacteria to aqueous (ethanolic and methanolic) rosemary and sage extracts and aqueous methanolic thyme extract. Klebsiella pneumoniae ATCC 13883 and Proteus vulgaris NCTC 4635 were more susceptible to the aqueous methanolic thyme extract. However, Listeria monocytogenes 1043S was the most sensitive to the aqueous ethanolic rosemary extract. Gram-positive bacteria were generally more sensitive to the tested extracts than Gram-negative ones.


Assuntos
Antibacterianos/farmacologia , Lamiaceae/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Fenóis/análise
8.
Front Microbiol ; 14: 1230025, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37692397

RESUMO

Introduction: This study aimed to assess the feasibility of utilizing commercially available dairy starter cultures to produce yogurt-type fermented soy beverages and evaluate the fundamental properties of the resulting products. Methods: Sixteen different starter cultures commonly used in the dairy industry for producing fermented milks, such as yogurt, were employed in the study. The study investigated the acidification curves, acidification kinetics, live cell population of starter microflora during refrigerated storage, pH changes, water-holding capacity, texture analysis, carbohydrates content, and fatty acid profile of the yogurt-type fermented soy beverage. Results and Discussion: The results demonstrated that the starter cultures exhibited distinct pH changes during the fermentation process, and these changes were statistically significant among the cultures. The acidification kinetics of different cultures of lactic acid bacteria showed characteristic patterns, which can be used to select the most suitable cultures for specific product production. The study also revealed that the choice of starter culture significantly influenced the starter microorganisms population in the yogurt-type fermented soy beverage. Additionally, the pH values and water-holding capacity of the beverages were affected by both the starter cultures and the duration of refrigerated storage. Texture analysis indicated that storage time had a significant impact on hardness and adhesiveness, with stabilization of these parameters observed after 7-21 days of storage. Furthermore, the fermentation process resulted in changes in the carbohydrate content of the soy beverages, which varied depending on the starter culture used.

9.
Microorganisms ; 11(6)2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37374980

RESUMO

This study aimed to investigate the ability of lactic acid bacteria to remove cholesterol in simulated gastric and intestinal fluids. The findings showed that the amount of cholesterol removed was dependent on the biomass, viability, and bacterial strain. Some cholesterol binding was stable and not released during gastrointestinal transit. The presence of cholesterol affected the fatty acid profile of bacterial cells, potentially influencing their metabolism and functioning. However, adding cholesterol did not significantly impact the survival of lactic acid bacteria during gastrointestinal transit. Storage time, passage, and bacterial culture type did not show significant effects on cholesterol content in fermented dairy products. Variations in cell survival were observed among lactic acid bacteria strains in simulated gastric and intestinal fluids, depending on the environment. Higher milk protein content was found to be more protective for bacterial cells during gastrointestinal transit than fat content. Future research should aim to better understand the impact of cholesterol on lactic acid bacteria metabolism and identify potential health benefits.

10.
Foods ; 12(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36765999

RESUMO

Herbs have been used for centuries in order to enrich food as preservatives, flavorings, and medicinal agents. The aim of this work was to study the effect of the addition of selected herbal extracts (dried leaves of Thymus vulgaris L., Origanum vulgare L., Satureja hortensis L., Rosmarinus officinalis L., and Ocimum basilicum L.) on selected parameters of fermented flavored cream (counts of starter culture bacteria and pH value) and the resulting flavored butter (water content, water distribution, butter plasma pH, butter fat acidity, and oxidative stability), preceded by a study of the activity of the herbal extracts against starter lactic acid bacteria determined using the well diffusion method. The extracts did not inhibit the starter lactic acid bacteria at a fixed level. The presence of the herbal extracts contributed to a shorter fermentation course and influenced the counts of starter culture bacteria during fermentation and refrigerated storage (at 5 °C) for 21 days. The extract additives did not affect the water content or the degree of its dispersion, the butter plasma pH, or the butter fat acidity. The positive effect of the rosemary and thyme extract addition was only noted when analyzing the oxidative stability of the milk fat of the butter.

11.
Parasitol Res ; 109(3): 591-4, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21344209

RESUMO

No fully effective approved drug therapy exists for Cryptosporidium infections of immunocompetent and immunocompromised patients. Here, we investigated 11 benzimidazole derivatives carrying substituted thioalkyl and thiobenzyl groups at position 2 of benzimidazole nucleus and additional substituents at the benzene part of benzimidazole for inhibition of the in vitro growth of the intestinal protozoan parasite, Cryptosporidium parvum. Three of them, i.e., 5-carboxy-2-(4-nitrobenzylthio)-1H-benzimidazole, 5,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, and 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, (compounds 5, 7, and 8) were the most active (IC(50) 28-31 µM). The concentration of compounds 5, 7, and 8 that caused 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was comparable with those obtained for paromomycin.


Assuntos
Antiprotozoários/farmacologia , Benzimidazóis/farmacologia , Cryptosporidium parvum/efeitos dos fármacos , Animais , Antiprotozoários/química , Benzimidazóis/química , Linhagem Celular , Sobrevivência Celular , Cryptosporidium parvum/crescimento & desenvolvimento , Enterócitos/parasitologia , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Parasitária
12.
Foods ; 10(2)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671224

RESUMO

The aim of the study was to evaluate the possibility to utilize a fish waste oil issued from the industrial smoking process in nitrogen-limited Yarrowia lipolytica yeast batch cultures. The waste carbon source was utilized by the yeast and stimulated the single cell oil production via an ex novo pathway. The yeast biomass contained lipids up to 0.227 g/g d.m.. Independently from culture conditions, high contents of very long chain fatty acids were quantified in yeast biomass including docosahexaenoic (DHA), eicosapentaenoic acid (EPA), eicosenic and erucic acids. The pH regulation did not influence the cellular lipids yield (0.234 g/g d.m.). Meanwhile, the intensification of the oxygenation of medium by changing the mixing speed (maximum concentration of lipids produced 4.64 g/dm3) and decreasing the amount of inoculum had a positive effect on the culture parameters in waste fish oil medium. Further work on upgradation of the original waste is advisable, especially because the oil indicated high content of polyphenols and lower susceptibility to oxidation than microbial oil derived from control olive oil medium.

13.
Biomolecules ; 10(1)2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31936515

RESUMO

The study aims to investigate the physicochemical properties and stability of the dispersion systems containing structured fats as a fatty base. In this work, calf tallow and pumpkin seed oil blends were chemically interesterified at various ratios (9:1, 3:1, 3:2, 3:3, 2:3, and 1:3) to produce structured lipids. Fatty acids composition, polar and nonpolar fraction content, and acid value were determined for the raw fats and interesterified blends. Afterwards, selected blends were applied in emulsion systems. Stability, microstructure, color and texture of emulsions were evaluated. The chemical interesterification had an effect on the modified blends properties, and caused an increase in polar fraction content and acid value, and a decrease in nonpolar fraction content. No effect on the fatty acids composition has been found. The evaluation of the prepared emulsions results allowed us to select two of the most stable and favorable samples-both containing chemically interesterified calf tallow and a pumpkin seed oil blend in a ratio of 1:3 as a fatty base, and xanthan gum or carboxymethylcellulose as a thickener. The obtained dispersions, containing fatty bases with improved physicochemical properties and desirable functionality, can be applied as food, cosmetic, and pharmaceutical emulsions.


Assuntos
Coloides/química , Cucurbita/química , Emulsões/química , Gorduras/química , Óleos de Plantas/química , Animais , Bovinos , Esterificação , Sementes/química
14.
Biomolecules ; 9(12)2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31835857

RESUMO

This study aimed at determining the effect of aqueous ethanolic extracts from lemon balm, hyssop and nettle, and butylated hydroxyanisole (BHA) on properties of shortbread cookies. This was achieved by instrumental measurements of color and sensory properties of the cookies directly after baking and by determination of peroxide (PV) and p-anisidine (p-AnV) values, and specific extinction coefficients (K232 and K268 values) for fat extracted from the cookies stored for 3 months at room temperature. Increase of the herbal extracts' concentration from 0.02% to 0.2% in the cookies caused a reduction of L* (the brightness) and a* values (the red coordinate), while b* values (the yellow coordinate) increased when the cookies were enriched with lemon balm and nettle extracts. Among the cookies studied, those prepared with BHA and 0.1 and 0.2% addition of lemon balm extracts were characterized by the highest scores for aroma, taste, and overall acceptability. Incorporation of BHA and 0.02% hyssop extract into the cookies caused a decrease of PV values (the peroxide value) for fat extracted from the cookies after 3 months of their storage compared to a (control) sample without additives and produced the lowest K232 values. Changes in the p-AnV values for the fat samples studied occurred gradually and slowly during the storage and the obtained values were lower compared to the control sample. All of the studied fat samples also showed a higher ability to scavenge DPPH radicals than the control sample. Considering both PV and p-AnV values as indicators of fat oxidation, BHA protected fat extracted from cookies against oxidation better than the herbal extracts used.


Assuntos
Cor , Gorduras na Dieta/análise , Alimentos/normas , Sequestradores de Radicais Livres/química , Extratos Vegetais/química , Plantas Medicinais/química , Compostos de Bifenilo/antagonistas & inibidores , Hidroxianisol Butilado/química , Sequestradores de Radicais Livres/farmacologia , Hyssopus/química , Melissa/química , Picratos/antagonistas & inibidores , Extratos Vegetais/farmacologia , Urtica dioica/química
15.
Acta Sci Pol Technol Aliment ; 16(1): 25-35, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28362470

RESUMO

BACKGROUND: Alongside flour, fat is the key ingredient of sponge cakes, including those with long shelf lives. It is an unstable food component, whose quality and nutritional safety depend on the composition and pres- ence of oxidation products. Consumption of fat oxidation products adversely affects the human body and contributes to the incidence of a number of medical conditions. Qualitative changes in fats extracted from thermostat sponge cakes with and without antioxidant additions were determined in this study. METHODS: In the study, two types of antioxidant were used: natural - green tea extract in three doses (0.02%; 0.2% and 1.0%) and synthetic BHA (0.02%) and 100%, solid bakery shortening. Sponge-cakes were thermostatted at temperatures 63°C after twenty-eight days. In this study, the quality of the lipid fraction was analyzed. The amount of primary (PV) and secondary (AnV) oxidation products was determined, and   a Rancimat test was performed. RESULTS: Adding antioxidants to fats varied in the degree to which oxidation processes of lipids fractions were inhibited. The peroxide value after twenty-eight days of thermostatting ranged from 3.57 meq O/kg (BHA) and 11.14 O meq/kg (extract content - 1%) to 62.85 meq O/kg (control sample). In turn, the value of AnV after the storage period ranged from 4.84 (BHA) and 6.71 (extract content - 1%) to 16.83 (control sample). CONCLUSIONS: The best protective effects in the process of oxidation was achieved by BHA. The longest in- duction time and the lowest peroxide value and anisidine value were obtained for this antioxidant. It was achieved after twenty-eight days of fat thermostatting. Nonetheless, the results demonstrated it is possible to use the commercially available green tea extract to slow the adverse process of fat oxidation in sponge cake products.


Assuntos
Antioxidantes/química , Alimentos , Lipídeos/química , Estresse Oxidativo , Extratos Vegetais/química , Chá/química , Oxirredução
16.
Food Chem ; 213: 450-456, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27451203

RESUMO

This study determined and compared the contents of bioactive components in plant seed oils extracted with n-hexane (Soxhlet method) and chloroform/methanol (Folch method) from coriander, caraway, anise, nutmeg and white mustard seeds. Oleic acid dominated among unsaturated fatty acids in nutmeg and anise seed oils while petroselinic acid was present in coriander and caraway oils. Concerning sterols, ß-sitosterol was the main component in seed oils extracted with both methods. The content of total phenolics in nutmeg, white mustard and coriander seed oils extracted with chloroform/methanol was higher than in their counterparts prepared with n-hexane. The seed oil samples extracted according to the Folch method exhibited a higher ability to scavenge DPPH radicals compared to the oil samples prepared with the Soxhlet method. DPPH values of the methanolic extracts derived from oils produced with the Folch method were also higher than in the oils extracted with n-hexane.


Assuntos
Antioxidantes/análise , Ácidos Graxos/análise , Fitosteróis/análise , Sementes , Antioxidantes/metabolismo , Coriandrum/química , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/metabolismo , Fitosteróis/metabolismo , Extratos Vegetais/análise , Extratos Vegetais/metabolismo , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Sementes/química , Especiarias/análise
17.
Wiad Parazytol ; 50(2): 143-50, 2004.
Artigo em Polonês | MEDLINE | ID: mdl-16859017

RESUMO

Studies on the occurrence of aquatic fungi in the bathing sites of the Suprasl River in Jurowce village were collected in years 2000-2003. Hydrochemical analysis was performed using standard methods. Bait method was used to isolate the fungi. In the Suprasl River at Jurowce village 36 fungi species were identified, among them fish pathogens Achlya orion, Aphanomyces laevis, Dictyuchus monosporus, Saprolegnia ferax, Saprolegnia monoica, S. parasitica, human pathogens Aspergillus flavus, Candida albicans, Lagenidium humanum, Penicillium mycetomagenum, Rhizophydium keratinophilum and Trichosporon cutaneum, phytopathogens Achlya racemosa, Phytophthora gonapodoides, Pythium butleri, P. myriotylum and P. debaryanum. Physicochemical parameters of waters in Suprasl River-bathing sites had no important effect on the occurrence of fungi.


Assuntos
Oomicetos/classificação , Rios/microbiologia , Microbiologia da Água , Poluição da Água/análise , Água/química , Animais , Monitoramento Ambiental , Doenças dos Peixes/microbiologia , Fungos/classificação , Fungos/isolamento & purificação , Fungos/fisiologia , Oomicetos/isolamento & purificação , Oomicetos/fisiologia , Polônia
18.
J Oleo Sci ; 62(4): 187-93, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23535304

RESUMO

A mixture of lard and rapeseed oil (1:1, wt/wt) was interesterified using immobilized lipases from Rhizomucor miehei (Lipozyme RM IM) and Candida antarctica (Novozym 435) as catalysts. Enzymatic interesterifications were carried out at 60°C for 8 h with Lipozyme RM IM or at 80°C for 4 h with Novozym 435. The biocatalyst doses were kept constant (8 wt-%). The starting blend was quantitatively separated by column chromatography into pure triacylglycerol fraction (98.5%), and a nontriacylglycerol fraction containing free fatty acids (0.3%) and of mono- and diacylglycerols (1.2%). It was found that after interesterification the contents of free fatty acids and of mono- and diacylglycerols increased to 3.5% and 6.3% or to 1.5% and 4.5% when Lipozyme RM IM and Novozym 435 were used, respectively.The slip melting temperatures and solid fat contents of the triacylglycerol fractions separated from interesterified samples were lower compared with the nonesterified blend. The sn-2 and sn-1,3 distribution of fatty acids in the triacylglycerol fractions before and after interesterification were determined. The compositions of fatty acids at sn-2 were near statistical (33.3%) when Novozym 435 was used. When Lipozyme RM IM was used, the fatty acid compositions at the sn-2 position remained practically unchanged, compared with the starting blend. The changes in molecular structures of fat components due to interesterification have greatly influenced on the melting profiles of products as illustrated by the DSC melting scans. The interesterified fats and isolated triacylglycerols had reduced oxidative stabilities, as assessed by Dynamic DSC and Isothermal PDSC measurements. The Arrhenius kinetic parameters for fats oxidation based on DSC and PDSC measurements were calculated.


Assuntos
Gorduras na Dieta/metabolismo , Lipase/metabolismo , Óleos de Plantas/metabolismo , Varredura Diferencial de Calorimetria , Candida/enzimologia , Diglicerídeos/metabolismo , Esterificação , Gorduras/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos Monoinsaturados , Oxirredução , Óleo de Brassica napus , Análise de Regressão , Rhizomucor/enzimologia , Temperatura , Triglicerídeos/metabolismo
19.
J Oleo Sci ; 62(11): 893-900, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24200936

RESUMO

Chicken fat and sunflower oil 2:3 m/m blend was enzymatically interesterified at 60°C with and without microwaves assistance. As the catalyst a commercial preparation of the immobilized lipase from Rhizomucor miehei (Lipozyme RM IM) containing 2% of water was used, and the catalyst load was 8% in each case. The starting mixture and the interesterified products were separated by column chromatography into pure triacylglycerols fraction (TAG) and a non-triacylglycerol fraction, which contained free fatty acids (FFA), mono- and diacylglycerols (MAG and DAG). The oxidative stabilities (OS) of fats studied and TAG derived from them were assessed by Rancimat at 100°C and by Pressure Differential Scanning Calorimetry (PDSC) under oxygen at 110-140°C. Interesterification reduced the OS of chicken fat and sunflower oil blend. The main factors influenced on the OS of fats studied were concentrations of tocopherols and presence of FFA, MAG- and DAG. The structures of TAGs were of minor importance. From the resulting PDSC exotherms their times to reach the onset (τon) and peak maximum (τmax) were measured and used for calculations of parameters of the Arrhenius type kinetics for thermaloxidative decomposition of fats studied.


Assuntos
Gorduras na Dieta , Óleos de Plantas/química , Animais , Varredura Diferencial de Calorimetria , Catálise , Galinhas , Gorduras na Dieta/análise , Gorduras na Dieta/isolamento & purificação , Diglicerídeos , Esterificação , Ácidos Graxos não Esterificados , Lipase , Monoglicerídeos , Oxirredução , Óleos de Plantas/isolamento & purificação , Rhizomucor/enzimologia , Óleo de Girassol , Temperatura , Tocoferóis/análise , Triglicerídeos/química , Água
20.
J Food Sci ; 77(9): C994-9, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22900972

RESUMO

The aim of this study was to establish the applicability of natural water-ethanol extracts of herbs and spices in increasing the oxidative stability of plant oils and in the production of novel food. Different concentrations (0, 100, 300, 500, and 700 ppm) of spice extracts and butylated hydroxyanisole (BHA) (100 ppm) were added to the studied oils. The antioxidant activity of spice extracts was determined with electron paramagnetic resonance (EPR) spectroscopy using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. The study showed that the extracts significantly increased the oxidative stability of the examined oils when compared to one of the strongest synthetic antioxidants--BHA. The applied simple production technology and addition of herb and spice extracts to plant oils enabled enhancement of their oxidative stability. The extracts are an alternative to the oils aromatized with an addition of fresh herbs, spices, and vegetables because it did not generate additional flavors thus enabling the maintenance of the characteristic ones. Moreover, it will increase the intake of natural substances in human diet, which are known to possess anticarcinogenic properties.


Assuntos
Antioxidantes/análise , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Extratos Vegetais/análise , Óleos de Plantas/química , Especiarias , Compostos de Bifenilo/análise , Hidroxianisol Butilado/análise , Oxirredução , Picratos/análise , Extratos Vegetais/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA