Occurrence of acrylamide carcinogen in Arabic coffee Qahwa, coffee and tea from Saudi Arabian market

Thermal Contaminants in Coffee Induced by Roasting: A Review

Roasting is responsible for imparting the main characteristics to coffee, but the high temperatures used in the process can lead to the formation of several potentially toxic substances. Among them, polycyclic aromatic hydrocarbons, acrylamide, furan and its derivative compounds, α-dicarbonyls and advanced glycation end products, 4-methylimidazole, and chloropropanols stand out. The objective of this review is to present a current and comprehensive overview of the chemical contaminants formed during coffee roasting, including a discussion of mitigation strategies reported in the literature to decrease the concentration of these toxicants. Although the formation of the contaminants occurs during the roasting step, knowledge of the coffee production chain as a whole is important to understand the main variables that will impact their concentrations in the different coffee products. The precursors and routes of formation are generally different for each contaminant, and the formed concentrations can be quite high for some substances. In addition, the study highlights several mitigation strategies related to decreasing the concentration of precursors, modifying process conditions and eliminating/degrading the formed contaminant. Many of these strategies show promising results, but there are still challenges to be overcome, since little information is available about advantages and disadvantages in relation to aspects such as costs, potential for application on an industrial scale and impacts on sensory properties.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

Biomedical rationale for acrylamide regulation and methods of detection

Acrylamide is the product of the Maillard reaction, which occurs when starchy, asparagine-rich foods including potato or grain products and coffee are fried, baked, roasted, or heated. Studies in rodents provide evidence that acrylamide is carcinogenic and a male reproductive harmful agent when administered in exceedingly high levels. A 2002 study identified acrylamide in popular consumer food and beverage products, stimulating the European Union (EU) and California to legislate public notice of acrylamide presence in fried and baked foods, and coffee products. The regulatory legislation enacted in the EU and California has scientists working to develop foods and processes aimed at reducing acrylamide formation and advancing rapid and accurate analytical methods for the quantitative and qualitative determination of acrylamide in food and beverage products. The purpose of this review is to survey the studies performed on rodents and humans that identified the potential health impact of acrylamide in the human diet, and provide insight into established and emerging analytical methods used to detect acrylamide in blood, aqueous samples, and food.

Contents of key bioactive and detrimental compounds in health performance coffees compared to conventional types of coffees sold in the United States market

The United States is the largest coffee consuming country worldwide. Recently, in addition to cup quality, the focus on health promotion has increased significantly in the country, with launching of many brands with health claims, mainly highlighting the antioxidative and stimulating properties of the beverage. On the other hand, mycotoxins and, to a lesser extent, acrylamide, have raised concerns among consumers and health authorities. This study investigated the contents of the main bioactive compounds (caffeine, chlorogenic acids and their 1,5-γ-quinolactones, and trigonelline) in health performance coffees and compared them to those of conventional roasted coffees available on the U.S. market. The following categories were compared by ANOVA at p ≤ 0.05, followed by Fisher's test: 1 - health performance, 2 - gourmet and 3 - traditional, totaling 127 samples. As complementary results, the contents of acrylamide and ochratoxin A were evaluated in part of the samples (n = 58). The mean contents (g per 100 g) of bioactive compounds for categories 1 to 3, respectively, were 1.09, 1.11 and 1.07 for caffeine; 1.75, 1.88 and 1.34 for chlorogenic acids/lactones, and 0.63, 0.64 and 0.56 for trigonelline. The mean contents (μg kg-1) of acrylamide for categories 1 to 3, respectively, were 82, 71 and 85. Only about 7% of the evaluated samples presented quantifiable amounts of OTA and all of them were within the maximum limits established by health authorities. In general, the contents of bioactive and potentially harmful compounds were not consistently different among categories, with high and low individual amounts in all of them. Most health claims on labels related to the amount of bioactive compounds in health performance coffees were unjustified, suggesting the need for improvement in coffee labeling regulation in the U.S.

Survey for acrylamide in processed foods from Korean market and individual exposure estimation using a non-parametric probabilistic model

Acrylamide, a known carcinogen, is formed during preparation of food containing reducing sugar and asparagine. Because acrylamide exposure of the population is primarily through food, the maximum levels of acrylamide in food were set by the European Commission in 2017. Moreover, in the 2016 Korean Total Diet study, acrylamide showed the lowest margin of exposure among 23 food-processing-related chemicals, necessitating risk reduction options. Therefore, the objective of this study was to determine the variation of acrylamide content in different food items and identify the food categories, to provide options for risk management. Acrylamide was analysed using high-performance liquid chromatography coupled with tandem mass spectrometry in more than 1,000 processed food items. To estimate acrylamide exposure, the analytical data obtained herein and the food consumption data of Korean National Health and Nutrition Examination Survey from 2013 to 2017 were used. A non-parametric technique of a probabilistic model was used for exposure estimation. Confectioneries (here this category includes potato and similar savoury snacks) contained a wide range of acrylamide content. Particularly, the highest acrylamide content was detected in a tea made of Jerusalem artichoke. The presence of acrylamide in turmeric along with the Jerusalem artichoke was reported in this study for the first time. The main contributors of dietary acrylamide exposure were confectioneries for youths aged 3-18 years and coffee for adults aged 19-80 years. Therefore, risk management in confectionery and coffee could help reduce acrylamide exposure for Koreans. In addition, the mitigation strategies for food containing high acrylamide content, such as Jerusalem artichoke tea, are needed to reduce acrylamide exposure to loyal consumers.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

The Effect of Different Roasting Durations on the Acrylamide Concentrations in the Arabic Coffee Beverages

Background:

Acrylamide is the most powerful carcinogenic and neurotoxic compound widely distributed in thermally processed foods. This compound is formed during early stages of roasting processes of coffee beans through Millard reaction between reducing sugars and asparagine. Due to the huge consumption of coffee throughout the globe, it has been considered as the major dietary source of this dangerous compound. Thus, this study aims to investigate the effect of roasting conditions on sugars and acrylamide contents in the Arabic coffee beans and beverages.

Methods:

Arabic coffee beans were roasted at 125°C for 30 to 60 min, ground to powders, brewed in boiling water for 20 min and then analysed for sugars and acrylamide contents.

Results:

Roasting conditions significantly (P ≤ 0.05) reduced the content of both reducing and nonreducing sugars compared to untreated samples. Increasing roasting duration to 40 min significantly (P ≤ 0.05) increased the acrylamide concentration values to the maximum, whereas extending the duration over 40 min (P ≤ 0.05) reduced the acrylamide concentration of coffee beans and beverages.

Conclusion:

The present study confirms that the process of roasting coffee beans is a significant factor in the formation of acrylamide in Arabic coffee powders and beverages.

Coffee consumption and risk of pancreatic cancer: a systematic review and dose-response meta-analysis

The association between coffee consumption and pancreatic cancer risk has been extensively studied; however, there is no consistent conclusion. Therefore, this meta-analysis study sought to evaluate dose-response relationship between them. A search was conducted using the PubMed and Web of Science databases. Thirteen high-quality cohort studies were identified, involving in 959,992 study participants and 3831 pancreatic cancer cases. Comparing the highest with lowest categories of coffee intake, the pooled relative risk (RR) was 1.08 (95% CI 0.94-1.25). For dose-response analysis, no evidence of a nonlinear dose-response association between coffee consumption and pancreatic cancer (p for nonlinearity =0.171) was found. The risk of pancreatic cancer was increased by 5.87% (RR =1.06, 95% CI 1.05-1.07) with the increment of one cup/day. Coffee consumption was identified to be related with the increasing risk of pancreatic cancer in a dose-response manner. Nevertheless, further mechanistic studies are needed to clarify the concerned issues.