Enzymatic Characterization of Pectinex XXL,a Pectinase Produced by Aspergillus niger,and Its Application in Fruit Juice Production

Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method.According to the results,the optimal pH for Pectinex XXL activity was 4.5,and the enzyme was stable in the pH range of 3.0~4.5.The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits.The optimal temperature for Pectinex XXL activity was 60℃,and the enzyme remained stable after one hour in a water bath set at 40℃.Additionally,the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na^(+),Mg^(2+),Ba^(2+),Co^(2+),Zn^(2+),and Fe^(2+),whereas it was slightly inhibited in the presence of 2 mmol/L of K^(+)and Fe^(2+)and partially inhibited in the presence of 1 and 2 mmol/L of Ca^(2+)and Mn^(2+),demonstrating its good stability in acids and excellent thermal catalytic performance.Based on the above experimental results,depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL.After one hour reaction with 16 U/mL of the enzyme,the yields of the plantain and cherry tomato juices were substantially increased by 119.03%and 15.97%,respectively,while their light transmittance was remarkably enhanced by 37.65%and 12.35%,respectively.Furthermore,the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29%and 29.50%,respectively.The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice,while effectively reducing its viscosity.These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.

Health effects of fruit juices and beverages with varying degrees of processing

The degree of processing is rarely considered an independent factor in the health effects of fruit juices and beverages(FJBs)consumption.In fact,the consumption of ultra-processed foods has been shown to pose health risks.In this study,we first integrated 4 systems used to classify the degree of food processing and then classified FJBs into three major categories,low(minimal),moderate and high.Second,we compared the differences in attitudes towards FJBs in dietary guidelines.Third,we integrated the results of existing epidemiological surveys,randomized controlled trials,and animal experiments to explore the health risks associated with consuming FJBs.Deepening the processing of FJBs has been found to lead to an increased risk of diseases.Dietary pattern,nutrients,addition agents and consumer preferences may be influential factors.Finally,we investigated whether there were any changes in the health benefits of 100%fruit juices produced by different processing methods.In conclusion,minimally/moderately processed 100%fruit juices provide more health benefits than highly processed fruit beverages.The results support the need to consider the extent of FJBs processing in future studies to adjust official nutritional recommendations for beverage consumption.

Assessment of Some Secondary Metabolites, Minerals and Alcohol Content of Noni Juice Obtained by Fermentation of Morinda citrifolia L. Fruit from Senegal

The fruit of Morinda citrifolia L., commonly known as noni, has an extensive history of use as a food and traditional medicine around the world. Adding value to Morinda citrifolia L. products, particularly the fruit, could be one way of building resilience in vulnerable farming households. The aim of this study was to determine the secondary metabolite and mineral composition of noni juice obtained by fermenting the fruit of Morinda citrifolia L. Fruits were collected in August 2022 from the local field in Thiès region, West of Senegal. Extraction yields were determined and the secondary metabolites were determined using conventional analytical methods. Calcium, magnesium, iron, sodium and potassium were determined by atomic absorption spectrophotometer coupled with a CCD detector. The results show that an average fruit mass (503.2 ± 110.96 g) consists of 171.44 ± 50.01 g pulp and 34.06 ± 10.35 g seeds. The traditional extraction yield of noni juice is 16.46% after three weeks of fermentation. The contents of total polyphenols, flavonoids and tannins obtained in noni are 608.97 ± 4.53 mg EAG/100mL, 7.78 ± 0.01 mg EQ/100mL and 0.191 ± 0.01 mg EC/100mL respectively. The ethanol content of noni varies from 3.57 to 5.23 mL/100mL during extraction. Noni has a high calcium content with a concentration of 383.79 ± 33.23 mg/L. This is followed by a good concentration of magnesium, potassium and sodium, at 278.47 ± 26.30, 187.43 ± 10.7 and 155.95 ± 28.66 mg/L respectively. Noni also has an iron content of 202.15 ± 0.05 mg/L.

Study on Compound Stabilizer Formulation for Mango Juice with Skin

[Objectives]The effects of stabilizers such as sodium carboxymethyl cellulose,pectin,sodium alginate and xanthan gum on the stability of mango juice with skin were discussed using mango as the raw material.[Methods]The formula and stability of mango beverage with skin were studied using mango juice with skin as the raw material.Four stabilizers,including pectin,sodium alginate and sodium carboxymethyl cellulose,were added to improve the stability of the juice.Based on single factor experiments and a response surface experiment,the stability model of mango juice was established to determine the best compound stabilizer.[Results]According to an orthogonal experiment on the stability of mango juice with skin,the optimum technical parameters were as follows:sodium carboxymethyl cellulose 0.20%,xanthan gum 0.08%,sodium alginate 0.18%,and pectin 0.14%,with which the optimal suspension stability was 69.12%.The optimum technical parameters from the response surface experiment were as follows:sodium carboxymethyl cellulose 0.199%,pectin 0.1185%,sodium alginate 0.163%,and xanthan gum 0.077%,with which the suspension stability was 70.32%.It was found that the stability of mango juice with skin obtained by the response surface experiment was better than that by the orthogonal experiment,and the order of factors affecting the stability of mango was sodium alginate(C)>sodium carboxymethyl cellulose(A)>pectin(D)>xanthan gum(B).[Conclusions]The formula of compound stabilizer for mango juice was optimized by the orthogonal experiment and the response surface method,providing a theoretical basis for the actual production of mango juice with skin.

Simultaneous Determination of Four Pesticide Residues in Fruit Juice by HPLC

[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction （SPE） cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels （0.1, 0.5 and 1.0 mg/kg） ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.

Study on Processing of Clear Banana Juice Using Hot Water Extraction Method

In this study, the effects of hot water temperature on clarity, total soluble solids, polyphenol oxidase （PPO） and color of banana juice during hot water ex-traction were discussed based on the theory in which heat treatment might induce the pectin and protein in banana pulp to form insoluble products. The results showed the hot water temperature had a significant effect on the formation of insol-uble polymers in banana pulp from pectin and protein. In 75 ℃ water, the pectin and protein in banana pulp were most inclined to form insoluble products. Under this condition, the clarity of banana juice was also highest. The light transmittance at 660 nm was close to 90%. In the banana juice, extracted by 75 ℃ water, the pectin and protein contents were lowest, and they were lower than 7.3 mg/100 ml and 12.9 mg/100 ml respectively. The 75 ℃ water could not inactivate completely the pectin in banana pulp due to its high heat resistance, Therefore, 0.05% L-cys-teine or ascorbic acid needed to be added into banana pulp to inhibit the browning of juice induced by residual PPO.

Detection of k-ras gene point mutation in fine needle aspiration and pancreatic juice by sequence special primer method and its clinical significance

INTRODUCTIONThe point mutation rate of k-ras gene at codon 12 inpancreatic adenocarcinoma is reported to be as highas 90%,and with no mutations in normalpancreas tissues or other pancreatic disorders.Wehave detected the presence of k-ras gene

Microbiome changes in the gastric mucosa and gastric juice in different histological stages of Helicobacter pylori-negative gastric cancers

BACKGROUND The gastric microbiota in patients with gastric cancer(GC)has received increasing attention,but the profiling of the gastric microbiome through the histological stages of gastric tumorigenesis remains poorly understood,especially for patients with Helicobacter pylori-negative GC(HPNGC).AIM To characterize microbial profiles of gastric mucosa and juice for HPNGC carcinogenesis and identify distinct taxa in precancerous lesions.METHODS The 16S rRNA gene analysis was performed on gastric mucosa from 134 Helicobacter pylori-negative cases,including 56 superficial gastritis(SG),9 atrophic gastritis(AG),27 intestinal metaplasia(IM),29 dysplasia(Dys),and 13 GC cases,to investigate differences in gastric microbial diversity and composition across the disease stages.In addition,paired gastric mucosa and juice samples from 18 SG,18 IM,and 18 Dys samples were analyzed.α-Diversity was measured by Shannon and Chao1 indexes,andβ-diversity was calculated using partial least squares discrimination analysis(PLS-DA).Differences in the microbial composition across disease stages in different sample types were assessed using the linear discriminant analysis effect size.RESULTS The diversity and composition of the bacterial microbiota in the gastric mucosa changed progressively across stages of gastric carcinogenesis.The diversity of the gastric mucosa microbiota was found to be significantly lower in the IM and Dys groups than in the SG group,and the patients with GC had the lowest bacterial community richness(P<0.05).Patients with IM and those with Dys had similar gastric mucosa microbiota profiles with Ralstonia and Rhodococcus as the predominant genera.Microbial network analysis showed that there was increasing correlation strength between IM and Dys(|correlation threshold|≥0.5,P<0.05).GC and its precancerous lesions have distinguishable bacterial taxa;our results identified HPNGC-associated bacteria Streptococcaceae and Lactobacillaceae(P<0.05).Additionally,across precancerous lesion stages from AG to Dys in Helicobacter pylori-negative patients,Burkholderiaceae abundance continuously increased,while Streptococcaceae and Prevotellaceae abundance presented a continuous downward trend.Furthermore,the microbial diversity was higher in gastric juice(P<0.001)than in the mucosa,while PLS-DA revealed a statistically significant difference between the two groups(ANOSIM,P=0.001).A significant difference in the microbial structure was identified,with Proteobacteria being more prevalent in the gastric mucosa and Firmicutes being more abundant in gastric juice.CONCLUSION Our results provide insights into potential taxonomic biomarkers for HPNGC and its precancerous stages and assist in predicting the prognosis of IM and Dys based on the mucosal microbiota profile.

Study on chronic pancreatitis and pancreatic cancer using MRS and pancreatic juice samples

AIM:To investigate the markers of pancreatic diseases and provide basic data and experimental methods for the diagnosis of pancreatic diseases.METHODS:There were 15 patients in the present study,among whom 10 had pancreatic cancer and 5,chronic pancreatitis.In all patients,pancreatic cancer or chronic pancreatitis was located on the head of the p-a-ncrea-s.Pa-thology da-ta-of a-ll p-a-tients wa-s confirmed by biopsy and surgery.Among the 10 patients with pancreatic cancer,3 people had a medical history of longterm alcohol consumption.Of 5 patients with chronic pancreatitis,4 men suffered from alcoholic chronic pancreatitis.Pancreatic juice samples were obtained from patients by endoscopic retrograde cholangiopancreatography.Magnetic resonance spectroscopyn was performed on an 11.7-T scanner (Bruker DRX-500) using Call-Purcell-Meiboom-Gill pulse sequences.The parameters were as follows:spectral width,15 KHz;time domain,64 K;number of scans,512;and acquisition time,2.128 s.RESULTS:The main component of pancreatic juice included leucine,iso-leucine,valine,lactate,alanine,acetate,aspartate,lysine,glycine,threonine,tyrosine,histidine,tryptophan,and phenylalanine.On performing 1D 1H and 2D total correlation spectroscopy,we found a triplet peak at the chemical shift of 1.19 ppm,which only appeared in the spectra of pancreatic juice obtained from patients with alcoholic chronic pancreatitis.This triplet peak was considered the resonance of the methyl of ethoxy group,which may be associated with the metabolism of alcohol in the pancreas.CONCLUSION:The triplet peak,at the chemical shift of 1.19 ppm is likely to be the characteristic metabolite of alcoholic chronic pancreatitis.

Carcinogenic potential of duodenal reflux juice from patients with long-standing postgastrectomy

AIM: To determine whether study on the carcinogenic potential of reflux juice from patients with remote gastrectomy could clarify the inherent relationship between duodenal reflux and gastric stump cancer. METHODS: A total of 37 reflux juice samples (13 Billroth I, 24 Billroth II) were employed in the present study. A two-stage transformation assay using BALB/c 3T3 cells was carried out to test the initiating or promoting activity of these samples. RESULTS: Two of 18 (11.1%) reflux samples exerted initiating activities, whereas 9/19 (47.4%) samples enhanced the MNNG-initiating cell transformation, suggesting the duodenal reflux juice might more frequently possess the tumor-promoter activity (P = 0.029). In addition, there was no difference in initiating activities of the samples irrespective of surgical procedures (P = 0.488), while Billroth II samples exhibited stronger tumor-promoter activity than Billroth I samples (P = 0.027). Furthermore, the promoter activities were well correlated with the histological changes of the stomas (r(s) = 0.625, P = 0.004), but neither their cytotoxicities nor initiating activities had this correlation (Probabilities were 0.523 and 0.085, respectively). CONCLUSION: The duodenal reflux juice from patients with remote postgastrectomy did have carcinogenic potential, and suggested that tumor-promoting activity should principally account for the high incidence of gastric cancer in gastrectomy patients. In contrast, it is difficult to explain the high stump-cancer incidence with the N-nitroso compounds theory-a popular theory for the intact stomach carcinogenesis, and it seemed to be justified to focus chemo-prevention of this cancer on the tumor-promoting potential of reflux juice.

Chemical composition, antioxidant activity and GC-MS analysis of juice and peel oil of grapefruit varieties cultivated in India

Citrus family especially Grapefruit,has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties.The juice and essential oil extracted from eight recently released grapefruit cultivars were used to study physicochemical and antioxidant properties.The total soluble solids(TSS),titratable acidity(TA) and pH of juice samples extracted from various grapefruit varieties differed significantly.The refractive index,specific gravity and optical rotation values for the oil varied from 1.473 to 1.396,0.863 to 0.847 and +93 to +86,respectively.The percent 2,2-diphenyl-1-picrylhydrazyl radical activity(% DPPH activity) and ferric reducing antioxidant power(FRAP) values for grapefruit juice and peel oil varied from 24.06 to 18.79,2.91 to 1.44 mmol g^–1 and 84.87 to 74.73,7.76 to 5.73 mmol g^-1,respectively.There were significant differences in physicochemical,antioxidant properties and volatile profiles of extracted juice and oil.The oil exhibited higher DPPH and FRAP values than the juice.Among different components identified which accounted for over 99% of the volatile fraction,limonene,myrcene,and benzopyran were major components in all oil samples.

Gastric juice acidity in upper gastrointestinal diseases

AIM: To search the independent factors determining gastric juice acidity and to investigate the acidity of gastric juices in various benign and malignant upper gastrointestinal diseases. METHODS: Fasting gastric juice acidity of 165 healthysubjects and 346 patients with esophageal ulcer (n = 21), gastric ulcer (n = 136), duodenal ulcer (n = 100) or gastric cancer (n = 89) were measured and compared. Additionally, gastric specimens were taken from the antrum and body for rapid urease test and histological examination. RESULTS: Multivariate analysis revealed that bile stain of gastric juice, high acute inflammatory score of the corpus, and atrophy of the corpus were independent risk factors for the development of gastric hypoacidity with odds ratios of 3.1 (95% CI: 1.3-7.3), 3.1 (95% CI: 1.2-7.9) and 3.5 (95% CI: 1.3-9.2). Esophageal ulcer and duodenal ulcer patients had a lower pH level (1.9 and 2.1 vs 2.9, both P < 0.05) of gastric juices than healthy subjects. In contrast, gastric ulcer and gastric cancer patients had a higher pH level (3.4 and 6.6 vs 2.9, both P < 0.001) than healthy controls. Hypoacidity existed in 22%, 5%, 29%, 5% and 88% of healthy subjects, esophageal ulcer, gastric ulcer, duodenal ulcer and gastric cancer patients, respectively. CONCLUSION: Bile reflux, atrophy and dense neutrophil infiltrate of the corpus are three independent factors determining the acidity of gastric juice.

Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements

In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (CDs). The structure and optical properties of CDs were investigated by TEM, XRD, XRF, UV-Vis, FTIR, and fluorescence spectroscopy. CDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the CDs and riboflavin was achieved with CDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an accurate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, CDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and <2.6% (n = 3), respectively. CDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of CDs and determination of riboflavin.

Application of principal component-radial basis function neural networks (PC-RBFNN) for the detection of water-adulterated bayberry juice by near-infrared spectroscopy

Near-infrared (NIR) spectroscopy combined with chemometrics techniques was used to classify the pure bayberry juice and the one adulterated with 10% (w/w) and 20% (w/w) water. Principal component analysis (PCA) was applied to reduce the dimensions of spectral data, give information regarding a potential capability of separation of objects, and provide principal component (PC) scores for radial basis function neural networks (RBFNN). RBFNN was used to detect bayberry juice adulterant. Multiplicative scatter correction (MSC) and standard normal variate (SNV) transformation were used to preprocess spectra. The results demonstrate that PC-RBFNN with optimum parameters can separate pure bayberry juice samples from water-adulterated bayberry at a recognition rate of 97.62%, but cannot clearly detect water levels in the adulterated bayberry juice. We conclude that NIR technology can be successfully applied to detect water-adulterated bayberry juice.

Isolation of a novel characterized Issatchenkia terricola from red raspberry fruits on the degradation of citric acid and enrichment of flavonoid and volatile profiles in fermented red raspberry juice

High content of citric acid in red raspberry juice leads to poor sensory experience. This study developed a feasible method to degrade citric acid in red raspberry juice using a novel characterized Issatchenkia terricola WJL-G4 isolated from red raspberry fruits. I. terricola WJL-G4 exhibited a potent capability of reducing the citric acid contents from(22.8 ± 0.08) g/L to(6.2 ± 0.02) g/L within 36 h fermentation, then completely depleted after 48 h. Furthermore, the contents of phenolic compound, including neochlorogenic acid, p-coumaric acid, raspberry ketone, and rutin significantly increased after 36 h fermentation. Fermentation increased total flavonoid contents in red raspberry juice, compared to that in control group. Volatile profiles exhibited to be enriched after fermentation, which contributed to the improvement of the juice taste. Our findings showed that I. terricola WJL-G4 can be applied in deacidification, enrichment of flavonoid compounds and volatile profiles in fermented red raspberry juice..

Extraction and Characterization of Antioxidant Compositions From Fermented Fruit Juice of Morinda citrifolia (Noni)

Extraction and characterization of antioxidative compositions from the extracts of fermented Xisha Noni （Morinda citrifolia L.） juice were studied. The antioxidative constituents of 184.6 g freeze-dried extracts of naturally fermented Xisha Noni juice were isolated successfully by petroleum ether, EtOAc and n-BuOH solvents, and the antioxidative effects were measured according to scavenging activity against hydroxyl generated in Fenton reaction system and superoxide anion radicals in pyrogallol autoxidation system. The EtOAc extract exhibited most significantly higher （P 〈 0.01） antioxidative activity than mannitol or vitamin C, while the petroleum ether and n-BuOH extracts showed lower activities compared to mannitol. Three antioxidant phenolic compounds, isoscopoletin, aesculetin and 3,3＇,4＇,5,7-pentahydroxyflavone （quercetin） were isolated from the EtOAc extract by several chromatography techniques for the first time. The results suggest that several compounds, in particular, the phenolic compounds, contribute separately or synergistically to the antioxidative activity of fermented Noni fruit juice.

Noni juice is not hepatotoxic

Noni juice （Morinda citrifolia） has been approved for use as a safe food within the European Union, following a review of safety. Since approval, three cases of acute hepatitis in Austrian noni juice consumers have been published, where a causal link is suggested between the liver dysfunction and ingestion of anthraquinones from the plant. Measurements of liver function in a human clinical safety study of TAHITIAN NONI Juice, as well as subacute and subchronic animal toxicity tests revealed no evidence of adverse liver effects at doses many times higher than those reported in the case studies. Additionally, M. citrifolia anthraquinones occur in the fruit in quantities too small to be of any toxicological significance. Further, these do not have chemical structures capable of being reduced to reactive anthrone radicals, which were implicated in previous cases of herbal hepototoxicity. The available data reveals no evidence of liver toxicity.

Role of pomegranate and citrus fruit juices in colon cancer prevention

Colorectal cancer is the second leading cause of cancer-related deaths in the United States.Recent studies prove that though chemotherapeutic agents are being used for the treatment of colon cancer,they become non-effective when the cancer progresses to an invasive stage.Since consumption of certain dietary agents has been linked with various cancers,fruit juices have been investigated for their consistently protective effect against colon cancer.The unique biochemical composition of fruit juices is responsible for their anticancer properties.In this review,the chemo-preventive effect of fruit juices such as pomegranate and citrus juices against colon cancer are discussed.For this purpose,the bioavailability,in vitro and in vivo effects of these fruit juices on colorectal cancer are highlighted.Moreover,there is a scarcity of studies involving human trials to estimate the preventive nature of these juices against colon cancer.This review will support the need for more preclinical tests with these crude juices and their constituents in different colorectal cancer cell lines and also some epidemiological studies in order to have a better understanding and promote pomegranate and citrus juices as crusaders against colon cancer.

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

Gastric juice for the diagnosis of H pylori infection in patients on proton pump inhibitors

AIM: To determine the efficacy of gastric juice polymerase chain reaction (PCR) for the detection of H pylori infection in comparison with histology and gastric antral biopsy PCR in patients on a proton pump inhibitor (PPI). METHODS: Eighty-five consecutive patients with dyspeptic symptoms were enrolled. Gastric biopsies for histology, PCR and gastric juice were collected at endoscopy for PCR of the H pylori urease C gene (ure C). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive and negative likelihood ratio for PCR of gastric juice for the H pylori ure C gene was compared to histology and gastric antral biopsy H pylori ure C PCR in patients with and without PPI. RESULTS: Gastric juice PCR was positive in 66 (78%) patients. Histology showed H pylori associated gastritis in 57 (67%). Gastric biopsy PCR was positive in 72 (85%). In patients not taking PPI, the sensitivity, specificity, PPV, NPV, accuracy and positive and negative likelihood ratio for gastric juice PCR were 89%, 72%, 91%, 67%, 90%, 85%, 3.1 and 0.1 respectively. In patients on PPI these values were 86%, 100%%, 100%, 29%, 86%, 9.5 and 1.4, respectively. CONCLUSION: Gastric juice PCR for the diagnosis of H pylori infection has increased sensitivity compared to histology with PPI. The use of gastric juice PCR is recommended to confirm H pylori status in patients taking PPIs.