ABSTRACT BACKGROUND: Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) in the liver of individuals with undetectable hepatitis B virus surface antigen (HBsAg) in the serum. The actual prevalence of OBI and its clinical relevance are not yet fully understood. OBJECTIVE: To evaluate the prevalence of HBV DNA in liver biopsies of HBsAg-negative patients with chronic liver disease of different etiologies in a referral center in Brazil and compare two different HBV DNA amplification protocols to detect HBV. DESIGN AND SETTING: This cross-sectional observational study was conducted at the Liver Outpatient Clinic, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, between January 2016 and December 2019. METHODS: HBV DNA was investigated in 104 liver biopsy samples from individuals with chronic liver disease of different etiologies, in whom HBsAg was undetectable in serum by nested-polymerase chain reaction (nested-PCR), using two different protocols. RESULTS: OBI, diagnosed by detecting HBV DNA using both protocols, was detected in 6.7% of the 104 individuals investigated. Both protocols showed a good reliability. CONCLUSION: In addition to the differences in the prevalence of HBV infection in different regions, variations in the polymerase chain reaction technique used for HBV DNA amplification may be responsible for the large variations in the prevalence of OBI identified in different studies. There is a need for better standardization of the diagnostic methods used to diagnose this entity.

Resumo: Introdução: O ensino da patologia, ciência que estuda as doenças e um dos ramos fundamentais da medicina, atravessa um período reflexivo sobre quais estratégias metodológicas se adaptam melhor à nova matriz curricular médica. Objetivo: Para o aprofundamento dessas reflexões à luz dos estudantes, o presente estudo analisou o comportamento e a preferência discentes em aulas práticas tradicionais e baseadas em problema na disciplina Anatomia Patológica II do curso de Medicina da Universidade Federal de Minas Gerais. Método: As análises qualitativas do comportamento e da preferência foram realizadas por meio da observação das aulas e da aplicação de questionário semiaberto, on-line e baseado na escala Likert. Resultado: Os resultados demostraram a clara preferência dos alunos pela metodologia ativa, tanto no que tange ao desenvolvimento das habilidades e competências estabelecidas para um eficiente ensino da patologia quanto no que concerne à participação em sala de aula. Conclusão: Assim, o estudo fortalece a importância da escuta acadêmica no planejamento do ensino da patologia.

Abstract: Introduction: The teaching of Pathology, a science that studies diseases and one of the fundamental branches of Medicine, is going through a period of reflection, in which methodological strategies are better suited to the new medical curriculum matrix. Objective: In order to expand these reflections in accordance with the students, the present study analyzed the students’ behavior and preferences in traditional and problem-based practical classes in the discipline of Pathological Anatomy II of the Medical course at Universidade Federal de Minas Gerais. Method: The qualitative analyses of behavior and preferences were carried out through the observation of classes and the application of a semi-open online questionnaire, based on the Likert scale. Result: The results showed the students’ obvious preference for the active methodology, both regarding the development of established skills and competences for an efficient teaching of Pathology, as well as participation in class. Conclusion: Therefore, the study reinforces the importance of academic listening when planning the teaching of Pathology.

ABSTRACT BACKGROUND: Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) deoxyribonucleic acid (DNA) in the liver of individuals with undetectable hepatitis B virus surface antigen (HBsAg) in the serum. The actual prevalence of OBI and its clinical relevance are not yet fully understood. OBJECTIVE: To evaluate the prevalence of HBV DNA in liver biopsies of HBsAg-negative patients with chronic liver disease of different etiologies in a referral center in Brazil and compare two different HBV DNA amplification protocols to detect HBV. DESIGN AND SETTING: This cross-sectional observational study was conducted at the Liver Outpatient Clinic, Hospital das Clínicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, between January 2016 and December 2019. METHODS: HBV DNA was investigated in 104 liver biopsy samples from individuals with chronic liver disease of different etiologies, in whom HBsAg was undetectable in serum by nested-polymerase chain reaction (nested-PCR), using two different protocols. RESULTS: OBI, diagnosed by detecting HBV DNA using both protocols, was detected in 6.7% of the 104 individuals investigated. Both protocols showed a good reliability. CONCLUSION: In addition to the differences in the prevalence of HBV infection in different regions, variations in the polymerase chain reaction technique used for HBV DNA amplification may be responsible for the large variations in the prevalence of OBI identified in different studies. There is a need for better standardization of the diagnostic methods used to diagnose this entity.

Resumo Fundamentos: Os mecanismos subjacentes pelos quais a doença cardíaca reumática (DCR) levam à disfunção valvar grave não são totalmente compreendidos. Objetivo: O presente estudo avaliou as alterações histopatológicas nas valvas mitrais (VM) buscando uma associação entre o padrão de disfunção valvar predominante e os achados histopatológicos. Métodos: Em 40 pacientes submetidos à troca da VM devido a DCR e em 20 controles submetidos a transplante cardíaco, foram analisados os aspectos histológicos da VM excisada. Dados clínicos e ecocardiográficos também foram coletados. As análises histológicas foram realizadas usando coloração com hematoxilina-eosina. Determinou-se inflamação, fibrose, neoangiogênese, calcificação e metaplasia adiposa. Valores de p<0,05 foram considerados estatisticamente significativos. Resultados: A idade média dos pacientes com DCR foi de 53±13 anos, sendo 36 (90%) do sexo feminino, enquanto a idade média dos controles foi de 50±12 anos, semelhante aos casos, sendo a maioria do sexo masculino (70%). O endocárdio valvar reumático apresentou espessura maior que os controles (1,3±0,5 mm versus 0,90±0,4 mm, p=0,003, respectivamente), e infiltrado inflamatório mais intenso no endocárdio (78% versus 36%; p=0,004), com predominância de células mononucleares. Ocorreu fibrose moderada a acentuada mais frequentemente em válvulas reumáticas do que em válvulas controle (100% vs. 29%; p<0,001). Ocorreu calcificação em 35% das valvas reumáticas, principalmente entre as valvas estenóticas, associada à área valvar mitral (p=0,003). Conclusões: Apesar do intenso grau de fibrose, o processo inflamatório permanece ativo na valva mitral reumática, mesmo em doença tardia com disfunção valvar. A calcificação predominou em valvas estenóticas e em pacientes com disfunção ventricular direita.

Abstract Background: The underlying mechanisms by which rheumatic heart disease (RHD) lead to severe valve dysfunction are not completely understood. Objective: The present study evaluated the histopathological changes in mitral valves (MV) seeking an association between the pattern of predominant valvular dysfunction and histopathological findings. Methods: In 40 patients who underwent MV replacement due to RHD, and in 20 controls that underwent heart transplant, histological aspects of the excised MV were analyzed. Clinical and echocardiographic data were also collected. Histological analyses were performed using hematoxylin-eosin staining. Inflammation, fibrosis, neoangiogenesis, calcification and adipose metaplasia were determined. A p value<0.05 was considered to be statistically significant. Results: The mean age of RHD patients was 53±13 years, 36 (90%) were female, whereas the mean age of controls was 50±12 years, similar to the cases, with the majority of males (70%). The rheumatic valve endocardium presented greater thickness than the controls (1.3±0.5 mm versus 0.90±0.4 mm, p=0.003, respectively), and a more intense inflammatory infiltrate in the endocardium (78% versus 36%; p=0.004), with predominance of mononuclear cells. Moderate to marked fibrosis occurred more frequently in rheumatic valves than in control valves (100% vs. 29%; p<0.001). Calcification occurred in 35% of rheumatic valves, especially among stenotic valves, which was associated with the mitral valve area (p=0.003). Conclusions: Despite intense degree of fibrosis, the inflammatory process remains active in the rheumatic mitral valve, even at late disease with valve dysfunction. Calcification predominated in stenotic valves and in patients with right ventricular dysfunction.

RESUMO Um dos principais desafios no manejo clínico do câncer de próstata é identificar qual tumor é agressivo e precisa de tratamento invasivo. Assim, ser capaz de prever qual irá progredir para recorrência bioquímica é uma ótima estratégia para estratificar pacientes com câncer de próstata. Pensando nisso, criamos uma fórmula matemática que leva em consideração os dados clínicos e patológicos resultando em uma variável quantitativa, denominada densidade de PSA da lesão, que tem potencial para predizer recidiva bioquímica. Para testar se nossa variável é capaz de predizer recorrência bioquímica, usamos uma coorte de 219 pacientes com câncer de próstata, associando nossas variáveis e parâmetros clássicos como a recorrência bioquímica. PSA total, peso da lesão, volume e densidade de PSA clássico foram associados com recorrência bioquímica (p<0,05). O escore ISUP também foi associado à recorrência bioquímica na biópsia e na amostra cirúrgica (p<0,001). O aumento da densidade do PSA da lesão foi significativamente associado à recidiva bioquímica (p=0,03). As variáveis ??derivadas da fórmula, PSA 15% e PSA 152, também foram associadas positivamente à recorrência bioquímica (p=0,01 e p=0,002 respectivamente). A análise de regressão logística mostra que a densidade do PSA clássico, do PSA da lesão e PSA total, juntos, podem explicar até 13% dos casos de recorrência. A densidade de PSA da lesão por si só poderia explicar até 7% dos casos de recorrência. Em conclusão, esta nova abordagem matemática pode ser uma ferramenta útil para prever a recorrência da doença no câncer de próstata.

ABSTRACT A main challenge in the clinical management of prostate cancer is to identify which tumor is aggressive and needs invasive treatment. Thus, being able to predict which cancer will progress to biochemical recurrence is a great strategy to stratify prostate cancer patients. With that in mind, we created a mathematical formula that takes into account the patients clinical and pathological data resulting in a quantitative variable, called PSA density of the lesion, which has the potential to predict biochemical recurrence. To test if our variable is able to predict biochemical recurrence, we use a cohort of 219 prostate cancer patients, associating our new variable and classic parameters of prostate cancer with biochemical recurrence. Total PSA, lesion weight, volume and classic PSA density were positively associated with biochemical recurrence (p<0.05). ISUP score was also associated with biochemical recurrence in both biopsy and surgical specimen (p<0.001). The increase of PSA density of the lesion was significantly associated with the biochemical recurrence (p=0.03). Variables derived from the formula, PSA 15% and PSA 152, were also positive associated with the biochemical recurrence (p=0.01 and p=0.002 respectively). Logistic regression analysis shows that classic PSA density, PSA density of the lesion and total PSA, together, can explain up to 13% of cases of biochemical recurrence. PSA density of the lesion alone would have the ability to explain up to 7% of cases of biochemical recurrence. In conclusion, this new mathematical approach could be a useful tool to predict disease recurrence in prostate cancer.

Abstract During the yellow fever (YF) outbreak in Brazil, many cases of fulminant hepatitis were seen, although mild to moderate hepatitis was mostly observed with complete recovery. This report presents a case of late-onset hepatitis due to YF relapse. The patient sought medical attention after jaundice recurrence 40 days after the first YF hepatitis episode. This case highlights the importance of patient follow-up after the complete resolution of YF symptoms and discharge.

BACKGROUND Leprosy is an infectious-contagious disease caused by Mycobacterium leprae that remain endemic in 105 countries. This neglected disease has a wide range of clinical and histopathological manifestations that are related to the host inflammatory and immune responses. More recently, the inflammasome has assumed a relevant role in the inflammatory response against microbiological agents. However, the involvement of inflammasome in leprosy remains poorly understood. OBJECTIVES The aim is to associate biomarkers of inflammasome with the different immunopathological forms of leprosy. METHODS We performed an observational, cross-sectional, and comparative study of the immunophenotypic expression of inflammasome-associated proteins in immunopathological forms of leprosy of 99 skin lesion samples by immunohistochemistry. The intensity and percentage of NLRP3, Caspase-1, Caspases-4/5, interleukin-1β and interleukin-18 immunoreactivities in the inflammatory infiltrate of skin biopsies were evaluated. FINDINGS Strong expression of NLRP3 and inflammatory Caspases-4/5 were observed in lepromatous leprosy (lepromatous pole). In addition, were observed low expression of caspase-1, interleukin-1β, and interleukin-18 in tuberculoid and lepromatous leprosy. The interpolar or borderline form showed immunophenotype predominantly similar to the lepromatous pole. MAIN CONCLUSIONS Our results demonstrate that the NLRP3 inflammasome is inactive in leprosy, suggesting immune evasion of M. leprae.

Abstract INTRODUCTION: The detection of Trypanosoma cruzi in tissue samples is important in many situations, such as testing of the reactivation of the infection. The detection of T. cruzi nests in endomyocardial biopsies (EMB) may be useful to evaluate graft rejection. Given their scarcity, such nests are not routinely identified. To increase the diagnosis sensitivity, immunohistochemistry (IHC) may serve as a promising strategy. Here, we validate an antiserum for the detection of T. cruzi infection by IHC. METHODS: We used 1) positive controls (PCs) - 13 EMB, 12 skin biopsies, and 1 heart with T. cruzi nests as sections stained with hematoxylin and eosin (HE); 2) negative controls - a) 10 explant hearts and 10 EMB with no amastigote nests or clinical/laboratory signs of chagasic infection; and b) eight samples with leishmaniasis, toxoplasmosis, or histoplasmosis; and 3) Cases - 31 EMB of chagasic patients with no parasite nests in HE sections but detected positive for T. cruzi DNA by polymerase chain reaction. As a primary antibody, a hyperimmune serum from T. cruzi-infected rabbits was used. RESULTS: IHC results were positive for 21 of 26 PCs (80.8%) and one case of cutaneous leishmaniasis. In 4 of 31 cases, IHC revealed nests (12.9%), which were undetected by conventional histological examination. CONCLUSIONS: This study shows that IHC with the tested antiserum increases the sensitivity of the diagnosis and may be recommended for routine use in EMB analyses of cardiac transplant patients with Chagas disease.

RESUMO: A Campomanesia adamantium é uma espécie frutífera nativa do Cerrado que se destaca pela utilização na alimentação, na medicina e como pasto apícola. A composição química dos óleos essenciais obtidos de plantas de uma mesma espécie pode sofrer variação de seus constituintes por influência de vários fatores incluindo o método de extração do óleo essencial, fatores ambientais, genéticos e ontogenéticos. Neste sentido, o presente trabalho tem como objetivo identificar a influencia do tempo de hidrodestilação sobre o teor e a composição química do óleo essencial das folhas de C. adamantium . Os tratamentos constituíram-se de cinco tempos de extração (1, 2, 3, 4 e 5 horas) utilizando aparelho Clevenger com cinco repetições, sendo o delineamento inteiramente casualizado. Foi observado que após duas horas de hidrodestilação o teor de óleo essencial permanece constante. Em relação aos constituintes químicos do óleo essencial ocorreu variação das proporções dos compostos em todos os tempos de hidrodestilação testados, os compostos sesquiterpenos oxigenados espatulenol e óxido cariofileno foram majoritários nos cinco tempos de hidrodestilação.

ABSTRACT: Campomanesia adamantium is a native fruit species of the Cerrado and is used in food and medicines and as bee pasture. The chemical composition of essential oils obtained from plants of the same species have varying constituent proportions due to the influence of extractive factors, environmental, genetic and ontogenetic. This study aimed to identify the influence of hydrodistillation time on the content and chemical composition of essential oil extracted from the leaves of C. adamantium . Treatments consisted of five extraction times (1, 2, 3, 4, and 5h) using Clevenger with five replications in a completely randomized design. It was observed that after two hours of hydrodistillation, the essential oil content remains constant. Regarding the chemical constituents of essential oil, variation of the proportions of the compounds tested occurred at all hydrodistillation times. The compounds spathulenol oxygenated sesquiterpenes and caryophyllene oxide were the majority in the five hydrodistillation times.

RESUMO: A família Annonaceae é constituída por cerca de 135 gêneros, com uma diversidade extensa de espécies com grande quantidade de compostos químicos diversificados, advindos do metabolismo secundário. Entretanto, as informações sobre a composição química de óleo essencial de várias espécies da família ainda são incipientes, como é o caso da Cardiopetalum calophyllum . O trabalho teve como objetivo caracterizar quimicamente o óleo essencial extraído de folhas, flores e frutos da C. calophyllum , coletadas em áreas típicas do Cerrado goiano. A extração do óleo essencial se deu pelo método de hidrodestilação em aparelho de clevenger por um período de 4 horas. A análise química do óleo essencial foi realizada por cromatografia gasosa acoplada à espectrometria de massas (CG-MS) e a identificação dos constituintes pela comparação dos espectros obtidos com os espectros disponíveis na literatura e pelo cálculo do índice de retenção (IR). Foram identificados 23 compostos no óleo essencial das folhas, em que o composto majoritário foi o sesquiterpeno oxigenado espatulenol (28,78%); nas flores, foram identificados 31 compostos com predominância dos sesquiterpenos hidrocarbonados germacreno-D (37,03%) e germacreno-B (13,72%); e, nos frutos, 17 compostos com predominância dos sesquiterpenos hidrocarbonados germareno-D (28,19%) e germacreno-B (20,90%) e do sesquiterpeno oxigenado espatulenol (11,53%). Este trabalho descreve pela primeira vez a composição química do óleo essencial das folhas, flores e frutos da C. calophyllum , contribuindo significativamente para o conhecimento químico da espécie.

ABSTRACT: The Annonaceae family consists of ~135 genera with diverse species and a large number of chemical compounds arising from the secondary metabolism. However, the chemical composition of the essential oil of several species of the family such as Cardiopetalum calophyllum has not been completely determined. In this study, the essential oils extracted from the leaves, flowers, and fruits of C. calophyllum , collected in typical areas of the Cerrado of Goiás, were characterized. The essential oil was extracted by hydrodistillation for 4h using a Clevenger apparatus. The chemical analysis was carried out by gas chromatography-mass spectrometry (GC-MS), and the constituents were identified by comparing the spectra and retention index obtained with those available in the literature. Twenty three compounds were identified in the essential oil of leaves; the oxygenated sesquiterpene, spathulenol (28.78%), was the major compound. Twenty five compounds were identified in the flowers, mainly comprising sesquiterpene hydrocarbons, germacrene-D (37.03%) and germacrene-B (13.72%). Seventeen compounds were reported in fruits, mainly comprising sesquiterpene hydrocarbons, germacrene-D (28.19%) and germacrene-B (20.90%), and an oxygenated sesquiterpene, spathulenol (11.53%). This is the first report on the chemical composition of the essential oils from leaves, flowers, and fruits of C. calophyllum.

Understanding the social conditions and immunological characteristics that allow some human immunodeficiency virus (HIV)-exposed patients to remain uninfected represents an on-going challenge. In this study, the socio-demographic and sexual behaviour characteristics and immune activation profiles of uninfected individuals exposed to HIV-infected partners were investigated. A confidential and detailed questionnaire was administered and venous blood was tested using HIV-1/enzyme immunoassays, plasma HIV-1 RNA levels/bDNA and immunophenotyping/flow cytometry to determine the frequencies of CD4 and CD8 T cells expressing activation markers. The data analysis showed significant differences (p < 0.05) for immune parameters in individuals who were uninfected, albeit exposed to HIV-infected partners, compared with unexposed individuals. In particular, the exposed, uninfected individuals had a higher frequency (median, minimum-maximum) of CD4+HLA-DR+ (4.2, 1.8-6.1), CD8+HLA-DR+ (4.6, 0.9-13.7), CD4+CD45RO+ (27.5, 14.2-46.6), CD4+CD45RO+CD62L+ (46.7, 33.9-67.1), CD8+CD45RA+HLA-DR+ (12.1, 3.4-35.8) and CD8+CD45RO+HLA-DR+ (9.0, 3.2-14.8) cells, a decreased percentage of CD8+CD28+ cells (11.7, 4.5-24.0) and a lower cell-surface expression of Fcγ-R/CD16 on monocytes (56.5, 22.0-130.0). The plasma HIV-1 RNA levels demonstrated detectable RNA virus loads in 57% of the HIV-1+ female partners. These findings demonstrate an activation profile in both CD4 and CD8 peripheral T cells from HIV-1 exposed seronegative individuals of serodiscordant couples from a referral centre in Belo Horizonte, state of Minas Gerais.

OBJETIVO: Estudar a influência da glutamina em alterações funcionais e morfológicas do fígado na obstrução biliar extra-hepática por meio de um modelo experimental desenvolvido em ratos. MÉTODOS: Setenta ratos Wistar distribuídos em quatro grupos: controle (grupo C); operação fictícia (grupo OF), submetido à laparotomia com manuseio das vias biliares, mas sem ligadura do ducto hepático; (grupo OBE), submetido à laparotomia exploradora e ligadura do ducto hepático, sendo um deles submetido à suplementação com glutamina a 2% (grupo G). O grupo controle era composto por seis animais. Os animais dos grupos OF, OBE e G foram divididos em três grupos compostos por seis animais cada e que foram sacrificados no 7°, 14° e 21° dias após a operação, respectivamente. Foi colhido sangue para análise bioquímica e um fragmento de tecido hepático do lobo médio para estudo histológico. RESULTADOS: Tanto em relação à analise bioquímica (BT, aspartate and alanine aminotransferase AST, ALT e FAL) quanto em relação às alterações histopatológicas (fibrose, inflamação portal, inflamação parenquimatosa, alterações hepatocíticas e proliferação de ducto), não houve diferença estatística entre os grupos submetido a obstrução biliar extra-hepática sem (OBE) e com tratamento com glutamina (G). CONCLUSÃO: A suplementação com glutamina não alterou o prognóstico em relação às enzimas hepáticas e alterações histopatológicas nos animais submetidos à obstrução biliar extra-hepática.

PURPOSE: To study the influence of glutamine on functional and morphological changes of liver in the extrahepatic biliary obstruction through an experimental model in rats. METHODS: Seventy Wistar rats were divided into four groups: control (group C) fictitious operation, (group FO), submitted to laparotomy with handling of bile ducts, but without hepatic duct ligation, (group EBO) submitted to laparotomy and hepatic duct ligation, one of them submitted to supplementation with glutamine 2% (group G). The control group consisted of 6 animals. The animals from groups FO, EBO and G were divided into three groups consisting of 6 animals each, being sacrificed at 7, 14 and 21 days after operation, respectively. Blood samples were collected for biochemical analysis and a fragment of liver tissue was collected from the middle lobe for histological analysis. RESULTS: Both for biochemical analysis (BT, aspartate and alanine aminotransferase AST, ALT and alkaline phosphatase FAL) and for histopathological changes (fibrosis, portal inflammation, parenchymal inflammation, hepatocytic changes and duct proliferation), no statistical difference between groups submitted to extrahepatic biliary obstruction (EBO) with and without treatment with glutamine (G) was observed. CONCLUSION: Glutamine supplementation did not alter the prognosis of liver enzymes and histopathological changes in animals submitted to extrahepatic biliary obstruction.

A avaliação da contaminação, de estetoscópios utilizados em setores pediátricos de hospital e emergência, mostrou que 87% dos estetoscópios apresentaram diafragmas contaminados. O microrganismo mais freqüentemente isolado foi Staphylococcus coagulase negativo. A resistência aos antibióticos mostra que o estetoscópio deve ser considerado um importante veículo de bactérias resistentes aos antibióticos.

Evaluation of the contamination of stethoscopes used in pediatric units of a hospital and emergency service showed that 87% of them presented contaminated diaphragms. Coagulase-negative Staphylococcus was the microorganism most frequently isolated. The resistance to antibiotics indicates that stethoscopes should be considered to be an important vehicle for disseminating bacteria resistant to antibiotics.

Desde os primórdios dos tempos as antocianinas são extraídas de vegetais, mas avanços que garantam um processo viável e rentável exigem conhecimento, quantificação e controle das condições de operação. Estudos em batelada sob várias condições de extração indicaram que ácido acético em solução aquosa (10% V/V) foi o melhor solvente, quando usado na proporção de 0,25 g de repolho roxo mL-1. Nesta condição de operação foram feitos ensaios em coluna para avaliar a influência da força iônica, pH, taxa de escoamento do solvente, volume recirculado da solução de extração e massa de repolho roxo. Os resultados mostraram que o pH, recirculação e massa de repolho foram estatisticamente significativos, e as condições ótimas de operação encontradas para o processo foram pH 2,3, volume de solvente recirculado de 0,83 L e massa de repolho roxo igual a 50g.

The aim of this work was to extract anthocyanins from the red cabbage. Batch studies under several extraction conditions indicated that acetic acid in aqueous solution (10% V/V) was the best solvent, used in the proportion of 0.25 g of red cabbage mL-1. At this condition, column assays were carried out to evaluate the influence of the ionic force, pH, solvent flow rate, recirculated volume of red cabbage juice and the mass of red cabbage. Results showed that the pH, recirculation and mass of red cabbage had statistically significant effects, where the optimum operation conditions found for the process were pH 2.3, recirculation volume of the solvent 0.83 L and mass of red cabbage 50 g.