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1.
J Adolesc Health ; 74(4): 729-738, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38310505

ABSTRACT

PURPOSE: There is great interest in examining the consequences of the COVID-19 pandemic on adolescent mental health, but most studies were conducted in high-income countries. The identification of overall effects and protective factors is essential to understand the determinants of mental wellbeing in contexts of stress. We aimed to study changes in adolescent mental health during the pandemic and the risk and protective factors associated with these changes in a Brazilian birth cohort. METHODS: One thousand nine hundred forty nine adolescents from the 2004 Pelotas Birth Cohort were assessed prepandemic (T1, November 2019 to March 2020, mean age 15.69 years) and mid-pandemic (T2, August to December 2021, mean age 17.41 years). Mental health was assessed using the Strengths and Difficulties Questionnaire. Prepandemic and pandemic-related predictors were examined as predictors of change in multivariate latent change scores models. RESULTS: There was a mean increase in adolescent total mental health difficulties (M = 1.071, p < .001), hyperactivity/inattention (M = 0.208, p < .001), emotion symptoms (M = 0.409, p < .001), and peer problems (M = 0.434, p < .001) during the pandemic. This increase was associated with several negative family context variables, including harsh parenting and maternal depressive symptoms at T2. Higher emotion regulation levels protected against increases in adolescent mental health difficulties related to the COVID-19 pandemic. DISCUSSION: Family-context variables emerged as important risk factors for the deterioration of adolescent mental health during the COVID-19 pandemic. Interventions promoting emotion regulation strategies are a promising approach to protecting adolescent wellbeing in periods of stress.


Subject(s)
COVID-19 , Mental Health , Adolescent , Humans , Brazil/epidemiology , Adolescent Health , Birth Cohort , Pandemics , Parenting
2.
JCPP Adv ; 3(4): e12188, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38054047

ABSTRACT

Background: The negative impacts of maternal depression on child mental health outcomes are well-documented. However, some children show adaptive functioning following exposure to maternal depression, demonstrating resilience. In a large birth cohort from Brazil, a middle-income country, we examined direct and indirect pathways, considering socioeconomic, family, and individual factors, contributing to the development of resilience. Methods: Using data from the 2004 Pelotas Birth Cohort (N = 4231), we restricted the sample to those exposed to maternal depression up to age 6 years (depression present at ≥2 out of 5 assessment waves; n = 1132; 50% boys). Resilience was defined as scoring below or equal to the mean of the unexposed group on all four problem subscales of the parent-report Strengths and Difficulties Questionnaire at age 11 years. We examined pathways from socioeconomic status (SES; measured at birth) to resilience via cognitive stimulation (CS) (at 24 and 48 months) and Intelligence quotient (IQ) (at 6 years), and from CS to resilience via IQ, using counterfactual mediation. Results: A minority of children exposed to maternal depression showed resilience (12.4%). There was evidence of indirect pathways from SES to resilience via CS (odds ratio (OR) = 1.76, 95% confidence interval (CI) 1.02-3.38) and IQ (OR = 1.19, 95% CI 1.01-1.42), such that higher SES was associated with resilience via both higher levels of CS and higher IQ, which, in turn, were each positively associated with resilience. Furthermore, there was evidence of a direct (OR = 1.86, 95% CI 1.01-3.76) and total effect (OR = 1.94, 95% CI 1.05-3.89) of CS on resilience, even after controlling for SES. However, these effects varied depending on how persistent and severe depression was defined. Conclusions: These findings suggest that CS in early childhood may represent a modifiable protective factor for children exposed to maternal depression and a promising intervention target to promote child resilience in the context of maternal depression exposure.

3.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 45(5): 389-396, Sept.-Oct. 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1527995

ABSTRACT

Objectives: There is growing interest in examining the impacts of the coronavirus disease 2019 (COVID-19) pandemic on adolescent socioemotional development. This study aimed to examine changes in adolescent emotion regulation (ER), self-esteem (SE), and locus of control (LoC) from before to during the pandemic in a Brazilian birth cohort, and to investigate the variables associated with changes in those socioemotional competences. Methods: 1,949 adolescents from the 2004 Pelotas Birth Cohort were assessed before (T1, November 2019 to March 2020) and during (T2, August to December 2021) the COVID-19 pandemic (mean ages [SD] = 15.69 [0.19] and 17.41 [0.26], respectively). Adolescents' socioemotional competences were assessed, including ER, SE, and LoC. Sociodemographic, pre-pandemic, and pandemic-related correlates were examined as predictors of change. Multivariate latent change score models were used in the analyses. Results: There were significant mean increases in adolescents' ER and SE (mean ER = 1.918, p < 0.001; mean SE = 1.561, p = 0.001) and a significant mean decrease (towards internalization) in LoC levels (MLoC = -0.497, p < 0.01) during the pandemic. Factors that predicted a lower competency increase included family conflicts, harsh parenting, and maternal depressive symptoms during the pandemic. Conclusion: Despite the stress imposed by the COVID-19 pandemic, the adolescents of this cohort showed positive development in their socioemotional competences. Family-related factors emerged as important predictors of adolescent socioemotional adjustment during the study period.

4.
Braz J Psychiatry ; 45(5): 389-396, 2023.
Article in English | MEDLINE | ID: mdl-37400138

ABSTRACT

OBJECTIVES: There is growing interest in examining the impacts of the coronavirus disease 2019 (COVID-19) pandemic on adolescent socioemotional development. This study aimed to examine changes in adolescent emotion regulation (ER), self-esteem (SE), and locus of control (LoC) from before to during the pandemic in a Brazilian birth cohort, and to investigate the variables associated with changes in those socioemotional competences. METHODS: 1,949 adolescents from the 2004 Pelotas Birth Cohort were assessed before (T1, November 2019 to March 2020) and during (T2, August to December 2021) the COVID-19 pandemic (mean ages [SD] = 15.69 [0.19] and 17.41 [0.26], respectively). Adolescents' socioemotional competences were assessed, including ER, SE, and LoC. Sociodemographic, pre-pandemic, and pandemic-related correlates were examined as predictors of change. Multivariate latent change score models were used in the analyses. RESULTS: There were significant mean increases in adolescents' ER and SE (mean ER = 1.918, p < 0.001; mean SE = 1.561, p = 0.001) and a significant mean decrease (towards internalization) in LoC levels (MLoC = -0.497, p < 0.01) during the pandemic. Factors that predicted a lower competency increase included family conflicts, harsh parenting, and maternal depressive symptoms during the pandemic. CONCLUSION: Despite the stress imposed by the COVID-19 pandemic, the adolescents of this cohort showed positive development in their socioemotional competences. Family-related factors emerged as important predictors of adolescent socioemotional adjustment during the study period.


Subject(s)
COVID-19 , Emotional Regulation , Humans , Adolescent , Pandemics , Internal-External Control , Birth Cohort
5.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 45(2): 102-111, Mar.-Apr. 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1439563

ABSTRACT

Objectives: The objective of this study was to investigate the prevalence of the following risk behaviors: experimentation with cigarettes, electronic cigarettes, alcohol, substances, delinquent behavior, and sex at age 15, stratified by sex and socioeconomic position. We also investigated the prevalence of cigarette and alcohol experimentation at age 11 and the persistence and cumulative incidence of these behaviors between 11 and 15 years of age. Methods: In this cohort study, we included 3,491 11-year-olds and 1,949 15-year-olds from the 2004 Pelotas Birth Cohort. All outcomes were identified via confidential questionnaires and were analyzed as binary variables. Results: At age 11, there was a higher prevalence of cigarette experimentation among boys. At age 15, there was a higher prevalence of experimentation with alcohol, cigarettes, and substances among girls; experimentation with cigarettes and sex were more prevalent among those in a low socioeconomic position. We found a high cumulative incidence of alcohol experimentation, as well as persistent alcohol experimentation, in both boys and girls. Conclusions: Further research should clarify causal paths of the high prevalence of risk behaviors during adolescence and its increase among girls.

7.
Braz J Psychiatry ; 45(2): 93-101, 2023 May 11.
Article in English | MEDLINE | ID: mdl-36318481

ABSTRACT

OBJECTIVES: The objective of this study was to investigate the prevalence of the following risk behaviors: experimentation with cigarettes, electronic cigarettes, alcohol, substances, delinquent behavior, and sex at age 15, stratified by sex and socioeconomic position. We also investigated the prevalence of cigarette and alcohol experimentation at age 11 and the persistence and cumulative incidence of these behaviors between 11 and 15 years of age. METHODS: In this cohort study, we included 3,491 11-year-olds and 1,949 15-year-olds from the 2004 Pelotas Birth Cohort. All outcomes were identified via confidential questionnaires and were analyzed as binary variables. RESULTS: At age 11, there was a higher prevalence of cigarette experimentation among boys. At age 15, there was a higher prevalence of experimentation with alcohol, cigarettes, and substances among girls; experimentation with cigarettes and sex were more prevalent among those in a low socioeconomic position. We found a high cumulative incidence of alcohol experimentation, as well as persistent alcohol experimentation, in both boys and girls. CONCLUSION: Further research should clarify causal paths of the high prevalence of risk behaviors during adolescence and its increase among girls.


Subject(s)
Adolescent Behavior , Electronic Nicotine Delivery Systems , Male , Female , Humans , Adolescent , Child , Smoking/epidemiology , Cohort Studies , Birth Cohort , Prevalence , Risk-Taking
8.
Community Dent Oral Epidemiol ; 51(3): 575-582, 2023 06.
Article in English | MEDLINE | ID: mdl-36380436

ABSTRACT

OBJECTIVES: Previous cohort studies have found a positive association between prolonged breastfeeding (≥12 months) on dental caries, but few of them analysed the mediated effect of sugar consumption on this association. This study investigated whether prolonged breastfeeding is a risk factor for caries at 2-year follow-up assessment (21-27 months of age) and whether this effect is mediated by sugar consumption. METHODS: A birth cohort study was performed in the Brazilian Amazon (n = 800). Dental caries was assessed using the dmf-t index. Prolonged breastfeeding was the main exposure. Data on baseline covariables and sugar consumption at follow-up visits were analysed. We estimated the OR for total causal effect (TCE) and natural indirect effect (NIE) of prolonged breastfeeding on dental caries using the G-formula. RESULTS: The prevalence of caries was 22.8% (95% CI: 19.8%-25.8%). Children who were breastfed for 12-23 months (TCE = 1.13, 95% CI: 1.05-1.20) and for ≥24 months (TCE = 1.27, 95% CI: 1.14-1.40) presented a higher risk of caries at age of 2 years than those breastfed <12 months. However, this risk was slightly mediated by a decreased frequency of sugar consumption at age of 2 years only for breastfeeding from 12 to 23 months (NIE; OR = 0.95, 95% CI: 0.91-0.97). CONCLUSIONS: In this study, the effect of prolonged breastfeeding on the increased risk of dental caries was slightly mediated by sugar consumption. Early feeding practices for caries prevention and promoting breastfeeding while avoiding sugar consumption should be targeted in the first 2 years of life.


Subject(s)
Breast Feeding , Dental Caries , Child , Female , Humans , Child, Preschool , Breast Feeding/adverse effects , Cohort Studies , Dental Caries/epidemiology , Dental Caries/etiology , Dental Caries/prevention & control , Sugars , Dietary Sugars/adverse effects
9.
Eur Child Adolesc Psychiatry ; 32(10): 1935-1945, 2023 Oct.
Article in English | MEDLINE | ID: mdl-35731302

ABSTRACT

This study aimed to examine the impact of maternal depressive symptoms trajectories on 15-year-old adolescents' self-esteem and emotion regulation and test the mediating role of child maltreatment in this association. The 2004 Pelotas Birth Cohort is an ongoing cohort study originally comprised of 4231 live births in a southern Brazilian city. We examined a subsample of 1949 adolescents at age 15 years. Maternal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale. Trajectories of maternal depression from 3 months until the 11-year follow-up were calculated using a group-based modeling approach. Child maltreatment at age 11 years was measured using the parent-report version of the Parent-Child Conflict Tactics Scale. Adolescent outcomes at age 15 years were assessed by the self-report version of the Rosenberg Self-esteem Scale and the Emotion Regulation Index for Children and Adolescents. Path model analysis was conducted using a structural equation modeling framework in Mplus software. All maternal depression trajectories were negatively associated with offspring self-esteem and emotion regulation compared to the reference group (low depression trajectory). There was a significant indirect effect of maternal depression trajectories on emotion regulation mediated via child maltreatment. No evidence of moderation by sex was found for any pathway. The effects of maternal depression on adolescents' emotion regulation are partly mediated by child maltreatment at age 11.


Subject(s)
Child Abuse , Emotional Regulation , Humans , Adolescent , Child , Depression/psychology , Cohort Studies , Birth Cohort , Parents , Child Abuse/psychology
10.
Front Psychiatry ; 13: 1029048, 2022.
Article in English | MEDLINE | ID: mdl-36518365

ABSTRACT

Background: Maternal mental health problems are a serious public health concern. Previous data reported that pregnancy might have a protective effect against suicide. In contrast, more recent studies suggested that the prevalence of suicidal ideation (SI) is higher among pregnant women compared to the general population. Using a nationally representative population-based sample of Brazilian reproductive-aged women, this study aims to assess whether SI is more prevalent among pregnant women in comparison with nonpregnant woman. Methods: We used data from the Brazilian National Health Survey (PNS) of 2019, a cross-sectional study that comprised a representative sample of residents in private households in Brazil. For the analysis of this study, we selected women aged between 15 and 49 years old who have answered the questionnaire of the Selected Resident of the PNS, which comprised a sample of 27,249 women. Logistic regression models were performed to obtain crude and adjusted odds ratios (OR) and 95% confidence intervals (95%CI) for the association between pregnancy status and SI. Results: The prevalence of SI during pregnancy was 6.8% (95% CI: 6.2-7.4). The association between pregnancy status and SI was modified according to the recent clinical diagnosis of depression (interaction term: OR = 41.72, 95% CI: 5.64-308.45, p < 0.001). Our findings indicated that among nondepressed women, pregnancy status seems to decrease the probability of SI. Additionally, SI is associated with a vulnerable profile that includes being an adolescent, having an unpartnered/not married status, lower family income, lower education, and a recent clinical diagnosis of depression. Conclusion: SI is a common problem for reproductive-age women. In the presence of a recent depression clinical diagnosis, pregnancy increases the risk of SI. Management of SI among pregnant women should correctly identify sociodemographic risk factors and the presence of a recent clinical diagnosis of depression.

11.
Syst Rev ; 11(1): 190, 2022 09 05.
Article in English | MEDLINE | ID: mdl-36064439

ABSTRACT

BACKGROUND: Parental depression is associated with a range of mental health conditions and other difficulties in the offspring. Nevertheless, some offspring exposed to parental depression do not develop mental health problems, indicating the presence of protective factors that may buffer parental depression-related risk effects. However, evidence of protective factors that might explain good sustained mental health in offspring of depressed parents is limited and systematic synthesis of these factors is still needed. Therefore, as far as we are aware, this will be the first systematic review that will identify parent, family, child, social, and lifestyle factors associated with mental health resilience in offspring of depressed parents, examine evidence for sex-, developmental stage-, and outcome-specific factors and define mental health resilience in the parental depression context. METHODS: This protocol has been developed according to the PRISMA-P guidelines. Electronic searches will be performed for articles published up to 2022 in PsycINFO, Embase, MEDLINE, Web of Science Core Collection, and Cochrane Library. Two reviewers will independently screen titles/abstracts and full-texts against eligibility criteria, extract the data, and assess the overall quality of evidence. Both observational and RCT studies will be eligible for inclusion if they report offspring mental health resilience/outcome and depressive symptoms or depressive disorder in at least one of the parents/caregivers. Risk of bias will be assessed using The Joanna Briggs Institute (JBI) critical appraisal checklists and The Revised Cochrane risk of bias tool for randomised trials (RoB 2). It is expected that studies will be heterogeneous; therefore, meta-analysis will not be attempted. Studies will be systematically retrieved and collated using numerical, graphical, tabular, and narrative summaries and grouped by their design, scope, or overall quality. Further sub-group analyses will be performed to examine sex-, developmental stage-, and outcome-specific protective factors. DISCUSSION: The proposed systematic review will be the first to summarise and critically assess quality and strength of evidence of protective factors associated with mental health resilience in offspring of depressed parents. Directions and effect sizes of the protective factors will be discussed as well as differences between the studies, their limitations, and research gaps and future directions. Strengths and limitations of the proposed systematic review will be also discussed. The proposed systematic review findings are expected to help better understand mental health resilience and identify targets for evidence-based prevention and intervention strategies for those in need. SYSTEMATIC REVIEW REGISTRATION: A previous version of this systematic review protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) database ( www.crd.york.ac.uk/PROSPERO , CRD42021229955).


Subject(s)
Mental Disorders , Mental Health , Humans , Mental Disorders/prevention & control , Meta-Analysis as Topic , Parents , Systematic Reviews as Topic
12.
BMC Psychiatry ; 21(1): 18, 2021 01 07.
Article in English | MEDLINE | ID: mdl-33413253

ABSTRACT

BACKGROUND: This longitudinal study explored the relationship between trajectories of maternal depressive symptoms and offspring's risk behavior in adolescence contributing to an extremely scarce literature about the impacts of maternal depression trajectories on offspring risk behaviors. METHODS: We included 3437 11-year-old adolescents from the 2004 Pelotas Birth Cohort Study. Trajectories of maternal depressive symptoms were constructed using Edinburgh Postnatal Depression Scale (EDPS) from age 3 months to 11 years. We identified five trajectories of maternal depressive symptoms: "low" "moderate low", "increasing", "decreasing", and "chronic high". The following adolescent outcomes were identified via self-report questionnaire and analyzed as binary outcome -yes/no: involvement in fights and alcohol use at age 11. We used logistic regression models to examine the effects of trajectories of maternal depressive symptoms on offspring's risk behavior adjusting for potential confounding variable. RESULTS: Alcohol use and/or abuse as well as involvement in fights during adolescence, were not significantly associated with any specific trajectory of maternal depressive symptoms neither in the crude nor in the adjusted analyses. CONCLUSION: Alcohol use and involvement in fights at age 11 were not associated with any specific trajectory of maternal depression.


Subject(s)
Depression , Mothers , Adolescent , Child , Cohort Studies , Depression/epidemiology , Female , Humans , Longitudinal Studies , Risk-Taking
13.
Eur Child Adolesc Psychiatry ; 30(12): 1939-1948, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33098444

ABSTRACT

There is growing evidence that adolescent positive attributes and social aptitudes are associated with beneficial outcomes, including higher educational attainment and lower risk of later psychiatric disorder. Although maternal depression is a well-known risk factor for a variety of offspring adverse outcomes, less is known on its repercussion on children's positive behavioral traits. This study aimed to evaluate the impact of maternal depression trajectories on offspring positive attributes and social aptitudes, testing sex-moderated models for the studied association. The 2004 Pelotas Birth Cohort is an ongoing cohort originally comprised by 4231 live births from Brazil. We included 3465 11-year-old adolescents (48.6% female; maternal self-reported skin color: 27.0% non-white). Maternal depressive symptoms were assessed by the Edinburgh Postnatal Depression Scale (EPDS) at all follow-ups. Adolescent positive attributes and social aptitudes were ascertained by specific subscales of Development and Well-Being Assessment (DAWBA). Multivariate linear regression was used to examine the effect of maternal depression trajectories on offspring's outcomes, adjusting for potential confounding variables. Moderation was assessed with interaction terms. Adolescents from mothers who presented high-chronic levels of depressive symptoms during offspring's life have lower scores of positive attributes and social aptitudes. Boys exposed to maternal depression during their lifetime are more affected than girls regarding positive attributes, but this sex difference was not observed for social aptitudes. Interventions targeting the promotion of adaptive behavioral traits may represent an effective way to buffer the adverse impact of maternal depression on offspring development, especially for vulnerable groups such as male adolescents.


Subject(s)
Depression, Postpartum , Depression , Adolescent , Aptitude , Cohort Studies , Depression/epidemiology , Female , Humans , Longitudinal Studies , Male , Mothers
14.
Eur Child Adolesc Psychiatry ; 29(9): 1265-1276, 2020 Sep.
Article in English | MEDLINE | ID: mdl-31748986

ABSTRACT

The study aimed to explore associations between socioeconomic position (SEP) indicators, early child stimulation (ECS) and attention-related executive functions (EF) at age 11. Children born in Pelotas, Brazil, in 2004, were recruited to a birth cohort (n = 4231, non-response rate at recruitment < 1%) and followed from birth to age 11. SEP variables were family income and maternal schooling. At the 24 and 48-month follow-ups, five markers of cognitive stimulation and social interaction were recorded and positive answers were summed to a score ranging from 0 to 5. At age 11, attentional-switching and control, and selective-attention were assessed using the adapted Test-of-Everyday-Attention-for-Children (TEA-Ch). We used multivariable logistic regression models and mediation analysis to investigate potential mediator role of ECS in the association between SEP and EF. 3106 children were included in the analyses. Less than 7% of the more stimulated individuals showed low performance in attention-related EFs at age 11 compared with almost 20% in the bottom groups of stimulation. Higher child stimulation scores were associated with fewer impairments in attentional-control (OR adj 0.84; CI 95% 0.72-0.98) and attentional-switching (OR adj 0.85; CI 95% 0.73-0.99). Mediation analysis suggested that for attentional-switching, ECS mediated almost 20% of the total protective effect of maternal schooling for impaired EF. Assuming causal relationships, if maximum stimulation was provided to all children, the advantageous effect of maternal schooling on EF would be reduced by 47%. ECS may represent a protective factor for cognitive impairments in childhood and can be easily implemented at relatively low cost.


Subject(s)
Attention/physiology , Executive Function/physiology , Interpersonal Relations , Brazil , Child , Cohort Studies , Female , History, 21st Century , Humans , Male
15.
J Affect Disord ; 253: 8-17, 2019 06 15.
Article in English | MEDLINE | ID: mdl-31009846

ABSTRACT

BACKGROUND: Maternal depression is associated with impairments in child behavioural and emotional development, although the effect of exposure to maternal depression until adolescence is underexplored in most studies. This longitudinal study examined the association between maternal depressive symptoms trajectories and offspring socioemotional competences at age 11. METHODS: We included 3,437 11-year-old adolescents from the 2004 Pelotas Birth Cohort Study. Maternal depressive symptoms were assessed during the follow-up waves. Adolescent socioemotional competences were peer relationship problems and prosocial behaviour, both assessed by Strengths and Difficulties Questionnaire (SDQ), and Locus of Control (LoC), assessed by Nowick-Strickland Internal-External Scale. We used multivariate linear and logistic regression models to examine the effects of maternal depression trajectories on offspring's socioemotional competences, adjusting for potential confounding variables. RESULTS: We identified five trajectories of maternal depressive symptoms: a "low" trajectory (32.6%), a "moderate low" (42.2%), a "increasing" (11.1%), a "decreasing" (9.2%), and a "high-chronic" trajectory (4.9%). Adolescents whose mothers had persistent depressive symptoms, either intermediate or high, had greater levels of peer relationship problems and lower levels of prosocial behaviour than those whose mothers had low depressive symptoms. These differences were not explained by socioeconomic, maternal, and child characteristics. Maternal depressive symptoms during offspring's life was not a predictor of LoC orientation. LIMITATIONS: Nearly 20% of original cohort were not included in the analysis due to missing data. Adolescent's socioemotional competences were ascertained by maternal report. CONCLUSION: Our study extended the evidences of the negative impact of severe and recurrent maternal depression on offspring's socioemotional competences until early adolescence.


Subject(s)
Child of Impaired Parents/psychology , Depression/psychology , Mothers/psychology , Adult , Brazil/epidemiology , Child , Child of Impaired Parents/statistics & numerical data , Depression/epidemiology , Female , Humans , Logistic Models , Longitudinal Studies , Male
16.
Chem Phys Lipids ; 198: 1-9, 2016 06.
Article in English | MEDLINE | ID: mdl-27087282

ABSTRACT

The crystallization behavior of lipids has important implications in industrial processing of food products, whose physical characteristics depend largely on crystallized fats. The study of the crystallization behavior and polymorphism of a pure lipid system is of great scientific importance as a means of gaining an understanding of the phenomena involved, serving as basic knowledge to help guide the addition or removal of these compounds in different raw materials. The crystallization behavior and polymorphism of pure tripalmitin (PPP) and tristearin (SSS) were investigated by Polarized Light Microscopy (PLM) and Differential Scanning Calorimetry (DSC) under different crystallization conditions. The polymorphic forms (ß' and ß) of PPP and SSS exhibited different morphologies depending on how they were obtained, either from α form recrystallization or from isotropic melt. Crystallization in the ß form was faster in SSS than in PPP, indicating that the process occurs faster in TAGs composed of longer fatty acid chains. Both ß' and ß polymorphic forms were obtained from α form recrystallization, albeit with predominance of the ß form.


Subject(s)
Triglycerides/chemistry , Crystallization , Microscopy , Models, Molecular , Molecular Conformation , Temperature
17.
J Agric Food Chem ; 62(10): 2253-63, 2014 Mar 12.
Article in English | MEDLINE | ID: mdl-24547939

ABSTRACT

Two commercial emulsifiers (EM1 and EM2), containing predominantly monoacylglycerols (MAGs), were added in proportiond of 1.0 and 3.0% (w/w) to coconut oil and palm olein. EM1 consisted of approximately 90% MAGs, whereas EM2 consisted of approximately 50% MAGs. The crystallization behavior of these systems was evaluated by differential scanning calorimetry (DSC) and microscopy under polarized light. On the basis of DSC results, it was clear that the addition of EM2 accelerated the crystallization of coconut oil and delayed the crystallization of palm olein. In both oils EM2 addition led to the formation of smaller spherulites, and these effects improved the possibilities for using these fats as ingredients. In coconut oil the spherulites were maintained even at higher temperatures (20 °C). The addition of EM1 to coconut oil changed the crystallization pattern. In palm olein, the addition of 3.0% (w/w) of this emulsifier altered the pattern of crystallization of this fat.


Subject(s)
Emulsifying Agents/chemistry , Plant Oils/chemistry , Calorimetry, Differential Scanning , Coconut Oil , Crystallization , Fatty Acids/analysis , Microscopy, Polarization , Monoglycerides/chemistry , Palm Oil , Temperature , Triglycerides/analysis
18.
J Agric Food Chem ; 60(6): 1461-9, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22229347

ABSTRACT

trans-Free interesterified fat was produced for possible usage as a margarine. Palm stearin, coconut oil, and canola oil were used as substrates for chemical interesterification. The main aim of the present study was to evaluate the physicochemical properties of blends of palm stearin, coconut oil, and canola oil submitted to chemical interesterification using sodium methoxide as the catalyst. The original and interesterified blends were examined for fatty acid composition, softening and melting points, solid fat content, and consistency. Chemical interesterification reduced softening and melting points, consistency, and solid fat content. The interesterified fats showed desirable physicochemical properties for possible use as a margarine. Therefore, our result suggested that the interesterified fat without trans-fatty acids could be used as an alternative to partially hydrogenated fat.


Subject(s)
Fatty Acids, Monounsaturated/chemistry , Plant Oils/chemistry , Chemical Phenomena , Coconut Oil , Esterification , Fatty Acids/analysis , Palm Oil , Rapeseed Oil
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