Apple Juice Extract Research Articles

Histone-deacetylase inhibition and butyrate formation: Fecal slurry incubations with apple pectin and apple juice extracts

Objective Butyrate plays a major role among the short-chained fatty acids formed by the microbial flora of the colon. It is considered to be an important nutrient of the colon mucosa and has been shown to trigger differentiation and apoptosis of colon-derived cells in culture. Inhibition of histone deacetylase (HDAC) seems to play a central role in these effects. Butyrate was thus suggested to act as a chemopreventive metabolite that can prevent the occurrence of colorectal cancer, one of the most abundant types of cancer in Western industrialized countries. Some polymeric carbohydrates such as pectin, resistant to digestion in the small intestine, have been shown to serve as substrates for butyrate formation by the microflora of the colon. Methods In this study we investigated fermentation supernatants (FSs) from incubations of human fecal slurry with apple pectin and with polyphenol-rich apple juice extracts (AJEs). Results We found that FSs from fermentations with pectin were rich in butyrate and very active in HDAC inhibition in nuclear extracts prepared from the colon tumor cell lines HT-29 and Caco-2 and in intact HeLa Mad 38 cells bearing a reporter gene driven by HDAC inhibition. The butyrate levels explained most of the HDAC-inhibitory potency in FSs from pectin-rich fermentations. FSs from fermentations with AJEs showed lower butyrate yields but comparable HDAC inhibition. Combined incubations of pectin with AJEs led to effects similar to those with FSs from incubations with pectin as the only substrate added. These effects could not be explained by a direct HDAC-inhibitory potency of AJEs. Furthermore, the FSs were not cytotoxic at the HDAC-inhibitory concentrations. Conclusion These findings suggest that butyrate is the most relevant HDAC inhibitor formed in fermentations of human fecal slurry with apple pectin, whereas addition of AJEs leads to the formation of butyrate and other, yet unknown, HDAC inhibitors.

Content and mean polymerization degree of procyanidins in extracts obtained from clear and cloudy apple juices

The polyphenol profile of apples and that of technologically differently treated apple juices has already been studied thoroughly; nevertheless, the content of polymeric procyanidins has not received much attention up to date. Therefore, procyanidins in extracts made from six blended apple juices and two authentic clear as well as cloudy apple juices (Malus domestica cv. Bohnapfel and Bittenfelder) were investigated. Our determinations revealed significant differences in the total procyanidin content between apple juice extracts obtained from clear and the corresponding cloudy juices under study. Depending on the apple cultivars used average amounts of total procyanidin content determined in the extracts made from clear and cloudy juices ranged from 28.4 +/- 4.4% to 49.0 +/- 5.7% and from 48.3 +/- 0.3% to 60.6 +/- 0.3%, respectively. As the mean degree of polymerization (DPm) is supposed to have an influence on bioavailability and toxicity on different cells lines used in in vitro systems, the average degree of polymerization of the juices under examination were determined. Depending on the cultivar used and the technology of juice processing the DPm ranged between 3.0 and 13.4.

Apple Polyphenols Affect Protein Kinase C Activity and the Onset of Apoptosis in Human Colon Carcinoma Cells

Polyphenol-rich apple extracts have been reported to suppress human colon cancer cell growth in vitro. The protein kinase C (PKC) is among the signaling elements known to play an important role in colon carcinogenesis. In the present study, we investigated whether apple polyphenols affect PKC activity and induce apoptosis in the human colon carcinoma cell line HT29. A polyphenol-rich apple juice extract (AE02) was shown to inhibit cytosolic PKC activity in a cell-free system. In contrast, incubation of HT29 cells for 1 or 3 h with AE02 up to 2 mg/mL did not affect the cytosolic PKC activity. After prolonged incubation (24 h), cytosolic PKC activity was modulated, albeit a u-shaped curve of effectiveness was observed, with an initial inhibitory effect followed by the recurrence and even induction of enzyme activity. Concomitantly, in the cytosol, a significant decrease of the protein levels of PKCalpha, PKCbetaII, and PKCgamma together with a significant increase of a proapoptotic PKCdelta fragment was observed. However, the effects on the protein levels of these PKC isoforms in the cytosol were not associated with translocation between the different cellular compartments but might instead result from the onset of apoptosis. Indeed, the treatment with AE02 was shown to induce apoptosis by the activation of caspase-3, DNA fragmentation, and cleavage of poly(ADP ribose) polymerase. So far, identified and available constituents of the apple extract did not contribute substantially to the observed effects on PKC and apoptosis induction. In summary, apple polyphenols were found to inhibit PKC activity in a cell-free system. However, our results indicate that within intact cells PKC does not represent the primary target of apple polyphenols but appears to be affected in the course of apoptosis induction.

Apple polyphenols diminish the phosphorylation of the epidermal growth factor receptor in HT29 colon carcinoma cells

Previously, we showed that an apple juice extract (AE) potently inhibits the protein tyrosine kinase (PTK) activity of the epidermal growth factor receptor (EGFR). In the present study, an apple pomace extract (APE) was found to exceed the EGFR inhibitory properties of AE in a cell-free system. The impact of the extracts on the phosphorylation status of the EGFR in intact cells (HT29) was sensitive to catalase, added to suppress the accumulation of hydrogen peroxide. In the absence of catalase, the formation of hydrogen peroxide was observed, achieving 1.1 +/- 0.1 microM (AE) and 1.5 +/- 0.1 microM (APE) after 45 min of incubation. In the presence of catalase, suppressing the hydrogen peroxide level to the solvent control, APE effectively suppressed EGFR phosphorylation, even exceeding the effects of AE. Both extracts inhibited the growth of HT29 cells, albeit the enhanced EGFR inhibitory properties of APE compared to AE were not reflected by a higher growth inhibitory potential. The results clearly show that the effect of apple extracts on the EGFR and cell growth are not simply artefacts of hydrogen peroxide formation. However, the formation of hydrogen peroxide has to be considered to modulate and/or mask cellular responses to apple extracts.

Cider Proteins and Foam Characteristics: A Contribution to Their Characterization

A capillary sieving electrophoretic method for protein analysis and molecular weight determination was used to characterize ciders from Asturias, northern Spain. The total protein content (Bradford method) and the foam parameters (Bikerman method) were also analyzed to complete this characterization. The polypeptide profile, based on the molecular weight, together with exploratory and classification techniques, that is, principal component analysis (PCA) or linear discriminant analysis (LDA), allowed ciders to be differentiated on the basis of their foam assessment and the apple juice extraction technology used in the cidermaking process. In addition, the application of correlation analysis, that is, canonical correlations (CCA) or partial least-squares (PLS), revealed that the proteins with higher molecular weight were more relevant with respect to cider foamability. PLS analysis also provided a mathematical equation that is able to predict the stabilization time of foam from the polypeptide profile of the cider, because this is the foam parameter most influenced by these compounds.

Cytochrome P450 1A1 Expression and Activity in Caco-2 Cells: Modulation by Apple Juice Extract and Certain Apple Polyphenols

Cytochrome P450 (CYP) 1A1 plays a role in drug metabolism of intestinal cells (e.g., by activating certain chemical carcinogens such as polycyclic aromatic hydrocarbons into carcinogenic metabolites). In the human colon carcinoma cell line Caco-2, we investigated the effects of a defined polyphenolic apple juice extract (AJE), the major principle flavonoid/dihydrochalkone constituents quercetin and phloretin, and the corresponding prototype glycosides rutin and phlorizin on CYP1A1 expression and activity. Incubations were carried out with or without the potent aryl hydrocarbon receptor agonist/CYP1A1 inducer 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). AJE and quercetin acted as weak inducers of CYP1A1 mRNA and protein, and AJE, quercetin, and phlorizin led to a slight induction of CYP1A1-catalyzed 7-ethoxyresorufin O-deethylase (EROD) activity. However, AJE, quercetin, and phloretin were highly effective in suppressing CYP1A1 induction in co-incubations of the cells with 1 nM TCDD. The antagonistic effects were seen on the levels of mRNA, enzyme protein, and catalytic activity. In contrast, the related glycosides rutin and phlorizin were inactive as inducers or inhibitors. Inhibition of CYP1A1 induction was not related to general cytotoxicity, which could be completely abolished by the addition of ascorbic acid/alpha-tocopherol. AJE, quercetin, and phloretin also antagonized the TCDD-mediated induction of a reporter gene driven by a regulatory sequence of the human CYP1A1 gene promoter. Our findings suggest that apple juice extract can antagonize TCDD-mediated CYP1A1 induction by interfering with AhR-dependent gene transcription and by inhibiting the catalytic activity of CYP1A1. These effects may result in reduced metabolic activation of certain chemical carcinogens, in particular, under conditions of sustained AhR activation.

Avaliação do método de liquefação enzimática na extração de suco de maçã

O conceito da tecnologia limpa visa otimizar o processo de extração para obter o máximo de suco da fruta, diminuir perdas e gerenciar a aplicação do resíduo gerado. A utilização de complexos enzimáticos, constituídos por celulases e pectinases, na extração de suco permite, além de modificar características químicas e físico-químicas dos produtos, minimizar a geração de resíduos. O objetivo deste trabalho foi avaliar as condições de extração de suco de maçã por liquefação enzimática e comparar as características de qualidade dos produtos obtidos a partir desse método com os do tradicional processo de prensagem. Para o processo de liquefação, as melhores condições para obtenção de suco de maçã foram: enzimas 0,1 mL.Kg-1, temperatura 50 °C e tempo 75 min. O rendimento foi de 83,5% com a geração de 16,5% de bagaço, com uma diferença de 19%, quando comparado ao processamento de suco por prensagem. O suco obtido por liquefação foi mais ácido, apresentou maiores teores de cinzas e de nitrogênio do que o suco obtido por prensagem. No bagaço obtido por liquefação, os valores de acidez e cinzas, de extrato etéreo e de nitrogênio foram maiores do que no obtido por prensagem mas não houve diferença significativa nos teores de fibras alimentares embora os teores de pectina tenham sido mais baixos. Não foram detectadas diferenças significativas nas proporções de açúcares neutros relacionados à parede celular. O processamento por liquefação apresentou melhores resultados no rendimento do suco e na diminuição de bagaço, com uma vantagem de 18,5% sobre o processamento tradicional por prensagem.

Modulation of Key Elements of the Wnt Pathway by Apple Polyphenols

Glycogen synthase kinase-3beta (GSK3beta) is one of the key elements of the Wnt pathway involved in the regulation of beta-catenin homeostasis. The inhibition of GSK3beta kinase activity might lead to the onset of beta-catenin/TCF/LEF-mediated gene transcription, representing a potentially mitogenic stimulus. Apple polyphenols have been shown to mediate several biological effects that might be of interest with respect to chemoprevention. The objective of the study was to elucidate whether apple polyphenols also modulate key elements of the Wnt pathway, an effect that might limit the usefulness of these compounds for the prevention of carcinogenesis. A polyphenol-rich apple juice extract (AE02) was found to effectively inhibit the kinase activity of GSK3beta, immunoprecipitated from HT29 cells. Treatment of HT29 cells with AE02 for 24 h resulted in a concentration-dependent decrease of the cellular GSK3beta kinase activity. The inhibition of the kinase activity in HT29 cells was observed at polyphenol concentrations corresponding to the concentration of the constituents in the original apple juice. The apple characteristic dihydrochalcone glycoside phloridzin was found to be inactive up to 500 muM. The free aglycon phloretin as well as the flavonol quercetin effectively inhibited isolated GSK3beta, but did not affect the respective kinase activity within HT29 cells. In accordance with the inhibition of GSK3beta kinase activity by AE02, treatment of HT29 cells resulted in a significant decrease of phosphorylated beta-catenin. However, the total intracellular beta-catenin level was also found to be diminished, indicating that the interference of the apple constituents with GSK3beta was not associated with a stabilization of beta-catenin in HT29 cells. In line with these results, TCF/LEF-mediated gene transcription remained unaffected by treatment with AE02 as shown in a reporter gene approach. We can assume from the results that at consumer-relevant concentrations apple polyphenols do not mediate growth-stimulating effects in HT29 cells via the Wnt pathway.

Modulation of oxidative cell damage by reconstituted mixtures of phenolic apple juice extracts in human colon cell lines

Diets rich in fruits and vegetables are associated with a lower risk of tumour induction in the intestine and other sites. Apple juice with high amounts of antioxidative phenolics might protect the intestine against reactive oxygen species-mediated cell damage. We investigated to which extent the preventive effectiveness of polyphenolic juice extracts is governed by the amounts of five major constituents (rutin, phloridzin, chlorogenic acid, caffeic acid and epicatechin). In human colon cell lines (Caco-2, HT29), reconstituted mixtures of these phenolics were investigated in comparison to the original juice extracts, originating from cider and table apples. Parameters studied were (oxidative) DNA damage (Comet assay), cellular redox status (dichlorofluorescein assay) and Trolox equivalent antioxidant capacity (TEAC). The TEAC of the reconstituted mixtures was higher compared to the respective original extracts (4.7-7.3 mM vs. 3.6-4.2 mM Trolox). After 24 h cell incubation, menadione-induced (oxidative) DNA damage was more effectively reduced by the reconstituted mixtures (1-100 microg/mL, 24 h), as compared to the original extracts. In contrast, the cellular ROS level was reduced to a rather similar extent by original extracts and reconstituted mixtures. The results lead to the conclusion that the selected constituents in their authentic proportions substantially account for the antioxidative effectiveness of phenolic apple juice extracts.

Polyphenolic apple juice extracts and their major constituents reduce oxidative damage in human colon cell lines

Apple juice containing high amounts of antioxidative polyphenols might protect the intestine against oxidative cell damage. We investigated the preventive effectiveness of polyphenolic juice extracts of different origins (cider and table apples) in comparison to their major constituents in human colon cell lines (Caco-2, HT29). Parameters studied were (oxidative) DNA damage (Comet assay), glutathione level (photometric kinetic assay), cellular redox status (dichlorofluorescein assay) and antioxidant capacity. The extracts (50-250 microg/mL) modulated DNA damage and redox status in a concentration-dependent manner at 24-h incubation. The pomace extraction technology, applied for juice preparation, and the preferential selection of cider apple varieties influenced the polyphenolic pattern and increased the biological effectiveness of the extracts. The preventive potential of major juice constituents (1-100 microM, 24 h) strongly differed: rutin, epicatechin and caffeic acid clearly reduced (oxidative) DNA damage (Caco-2), chlorogenic acid efficiently decreased cellular reactive oxygen species level (HT29, Caco-2). The aglyca quercetin and phloretin exhibited the highest preventive/antioxidant capacity in all assays. The stability of the compounds inversely correlated with their preventive effectiveness and might contribute to the observed cell specific sensitivities. In conclusion, apple juice extracts distinctly reduce oxidative cell damage in human colon cell lines, an effect, which in part can be accounted for by their major constituents.

Natural cloudy apple juice and polyphenol-enriched apple juice extract prevent intestinal adenoma formation in the APCMin/+model for colon cancer prevention

Natural cloudy apple juice and polyphenol-enriched apple juice extract prevent intestinal adenoma formation in the APCMin/+model for colon cancer prevention

Inhibitors of the epidermal growth factor receptor in apple juice extract

The polyphenol-rich extract of a consumer-relevant apple juice blend was found to potently inhibit the growth of the human colon cancer cell line HT29 in vitro. The epidermal growth factor receptor (EGFR) and its subsequent signaling cascade play an important role in the regulation of cell proliferation in HT29 cells. The protein tyrosine kinase activity of an EGFR preparation was effectively inhibited by the polyphenol-rich apple juice extract. Treatment of intact cells with this extract resulted in the suppression of the subsequent mitogen-activated protein kinase cascade. Amongst the so far identified apple juice constituents, the proanthocyanidins B1 and B2 as well as quercetin-3-glc (isoquercitrin) and quercetin-3-gal (hyperoside) were found to possess substantial EGFR-inhibitory properties. However, as to be expected from the final concentration of these potential EGFR inhibitors in the original polyphenol-rich extract, a synthetic mixture of the apple juice constituents identified and available so far, including both proanthocyanidins and the quercetin glycosides, showed only marginal inhibitory effects on the EGFR. These results permit the assumption that yet unknown constituents contribute substantially to the potent EGFR-inhibitory properties of polyphenol-rich apple juice extract. In summary, the polyphenol composition of apple juice possesses promising growth-inhibitory properties, affecting proliferation-associated signaling cascades in colon tumor cells.

AVALIAÇÃO SENSORIAL DO SUCO DE MAÇÃ PROCESSADO COM CASCA DE ARROZ COMO COADJUVANTE DE PRENSAGEM

Suco de maçã da variedade Fuji processado com casca de arroz como auxiliar na prensagem foi avaliado sensorialmente. Na prensagem foi utilizada pressão de trabalho de 150 e 200kgf/cm² sobre a polpa triturada e adicionado casca de arroz nas concentrações de 0; 1; 3 e 5%. Após o processamento foram efetuadas avaliações de rendimento e sensoriais por equipe de julgadores treinados. A maior concentração de casca de arroz proporcionou maior incremento no rendimento de extração do suco de maçã, superior às médias das testemunhas. Na pressão de 150kgf/cm² a testemunha obteve um rendimento de 59,91%, enquanto a concentração com 5% de casca de arroz teve um rendimento de 76,09%. Para a pressão de 200kgf/cm², a testemunha apresentou média de 66,52% e a concentração com 5% de casca de arroz obteve o maior rendimento de extração, média de 73,19%. Na avaliação sensorial, observa-se diferença significativa entre as testemunhas e os tratamentos, especialmente quanto aos atributos cor, odor e sabor. Na qualidade geral, os sucos obtidos com o tratamento testemunha foram considerados de melhor qualidade que aqueles obtidos com os tratamentos onde foi adicionado auxiliar de prensagem casca de arroz, indicando que este tratamento influencia negativamente na qualidade final do produto.

Optimizing Apple Juice Extraction in Multiple Presses

: A method was developed to find the optimum hydration flow sheet that maximizes either the profit or the soluble solids recovery for a given number of presses in an apple concentrate juice plant. The pomace arising from a press can be wetted with either pure water or dilute juice from downstream presses, or a mixture of both in any proportion. The mass balance around the presses involving any hydration arrangement was posed as an array named connectivity matrix. The connectivity matrix and the economical balance were written in computer code in order to carry out the optimization procedure. The optimization started from a minimum amount of water, and stepwise increasing levels of hydration were evaluated. The best value of this combinatorial search was retained. The optimum arrangement was pure countercurrent in most of cases considered.

Capillary Gas Chromatography/Mass Spectrometry with Chemical Ionization and Negative Ion Detection for Confirmation of Identity of Patulin in Apple Juice

Gas chromatography/mass spectrometry (GC/MS) with negative ion chemical ionization permits detection of underivatized patulin in apple juice extracts while minimizing co-extractive responses. The technique has been used with a variety of capillary columns in quadrupole, ion trap, and magnetic sector GC/MS instruments to confirm presumptive findings of patulin in apple juice at concentrations ranging from 68 to 3700 micrograms/L. The demonstrated ability to use any of these 3 mass spectrometers and several capillary columns to confirm the identity of patulin are significant strengths of the technique.

Gas chromatography-mass spectrometry of Alternaria mycotoxins

Heptafluorobutyrate (HFB) derivatives have not previously been used for GC of Alternative mycotoxins. Capillary (0.5 μm film) GC-mass spectrometry (MS) showed that full and partial derivatives of alternariol (AOH), alternariol monomethyl ether (AME) and altenuene (ALT); a structurally uncharacterized derivative of altertoxin I (ALTX-I); and a tris-HFB derivative of tenuazonic acid (TA) were formed with heptafluorobutyric anhydride and a basic catalyst. Full and partial trimethylsilyl (TMS) ethers of these mycotoxins were formed with Tri-Sil TBT. Apple juice extracts caused increased response in GC-MS of AOH bis-HFB and bis-TMS derivatives. Natural occurrence of AOH in apple juice has been demonstrated.

Chemical characterization of high-yielding varieties of cashew (Anacardium occidentale)

Cashew apples and kernels from sixteen high-yielding varieties were chemically characterized. Protein, starch, amino acids and sodium contents in cashew kernels did not vary significantly among the high-yielding varieties. Reducing sugar content in the kernel was negligible compared to total sugar. Ascorbic acid, amino acid, phenol and tannin contents in cashew apple showed a significant variation among high-yielding varieties. Non-reducing sugar content in cashew apples was negligible. Varieties M 6/1, Bla 256-1, M 10/4 and M 44/3 appeared to be better for apple juice extraction because of their low tannin content. No varietal difference was noticed with respect to qualitative composition of sugars, organic acids and phenols.

Apple juice extraction in a counter‐current diffuser

SummaryMeasurements have been carried out on an industrial diffuser for the extraction of apple juice. Concentration profiles in the free juice and in the juice contained in the apple slices were measured at various temperatures and counter‐current flow rates. The data can be described by a theoretical model taking into account the time of plasmolysis as a function of temperature. Below around 58°C, the concentration profiles break into two parts—before and after plasmolysis—and the diffuser yield is lowered. The yield is also lowered if the water‐to‐apple volume ratio is not kept well above unity. Under optimal conditions it is possible to obtain an overall recovery of soluble matter from apple stock to final juice which is above 90%. The axial dispersion coefficient (‘eddy diffusion coefficient’) of the apple slices was also measured. At a mean speed of apple slices through the diffuser of about 0.06 m/min (holding time = 120 min), the axial dispersion coefficient was around 0.01 m2/min.

A comparison of two quantitative mass spectrometric methods for the analysis of patulin in apple juice

High resolution single ion monitoring and low resolution multiple ion monitoring without the use of an internal standard, were compared as methods for the mass spectrometric measurement of patulin in apple juice extracts. Single ion monitoring was the more sensitive method and reliably measured 0.2 ppb patulin in apple juice while multiple ion monitoring gave a detection limit of 5 ppb and could reliably measure 10 ppb. A perdeuterated analogue of silylated patulin was found to be unsuitable either as an internal standard or as a carrier.

Collaborative Study of a Chromatographic Method for Determination of Patulin in Apple Juice

Abstract Collaborators in 20 laboratories studied a method for the determination of patulin in apple juice. The collaborators mixed patulin solutions with the apple juice to obtain 9 spiked samples (of which 2 were blanks) and 1 practice sample. After column chromatography of the apple juice extract, patulin was estimated visually by thin layer chromatography, using 3-methyl-2-benzothiazolinone hydrazone.HCl as the spray reagent. Mean recoveries of patulin ranged from 69.8 to 98.3% for 3 contamination levels. The method has been adopted as official first action for the determination of patulin in apple juice.