Effect of processing on ochratoxin A (OTA) content of coffee

Coffee production can be roughly separated into three main steps 1) cherry processing to green coffee beans, 2) storage and transportation of green coffee to the place of consumption, and 3) green coffee processing to roasted and ground coffee and soluble coffee. The mold species which are known to produce ochratoxin A (OTA) in coffee have been identified as Aspergillus ochraceus, A. carbonarius and occasionally, A. niger. The length of time spent at a water activity > 0.80 at any moment until roasting defines the risk of mold growth and OTA production. However, the specific moment and locus of contamination have not yet been clearly identified. Since coffee husks are a significant source of OTA contamination, cleaning and grading of green coffee are effective methods for reducing OTA levels in coffee. During the process of converting green coffee to roasted and soluble coffees, up to 90% reduction in OTA levels can occur.

Behavior of Ochratoxin A during Green Coffee Roasting and Soluble Coffee Manufacture

As considerable inconsistencies are found in the literature regarding the influence of roasting and subsequent operations on the ochratoxin A (OTA) content of green coffee, experiments were undertaken to assess the evolution of OTA along an industrial soluble coffee manufacturing line. Both the variability and the amount of OTA naturally present in a lot of Thai Robusta green coffee were drastically reduced during soluble coffee manufacture. A small proportion of OTA was eliminated during green coffee cleaning, but the most significant reduction took place during roasting. The roast and ground coffee contained only 16% of the OTA originally present in the green coffee. Two phenomena are responsible for the elimination of OTA during roasting: a thermal degradation and a removal with chaff. Thermal degradation is the most important route of elimination, with <20% accounted for by the chaff. A further 20% reduction was observed during soluble coffee manufacture, so that the powder contained only 13% of the OTA initially present in the green beans.

Adulteration of soluble coffee with coffee husks and parchments

Commercial soluble coffee can be adulterated with coffee husks or parchments. Xylose is a good tracer for this type of mispractice. The analysis of total xylose in a wide selection of green beans and the assessment of its fate during processing allowed the derivation of a maximum total xylose limit of 0.40%, above which a soluble coffee should be considered as adulterated. Out of the 700 commercial soluble coffees analyzed, 81 exhibited a total xylose level above this limit. Of the samples with total xylose level lower than the limit, 99% displayed concentrations in free mannitol and total glucose below 0.30 and 2.10%, respectively.

Identity of the cholesterol-raising factor from boiled coffee and its effects on liver function enzymes

Boiled coffee contains an unidentified lipid that raises serum cholesterol. We studied the effects of the ingestion of coffee oil fractions of increasing purity in volunteers in order to identify the cholesterol-raising factor. In 15 volunteers who ingested 0.75 g/d of a non-triglyceride-fraction from coffee oil for 4 weeks, mean cholesterol increased by 48 mg/dl (1.2 mmol/l) relative to placebo. In contrast, a coffee oil stripped of the non-triglyceride lipids cafestol and kahweol had no effect. In three volunteers, purified cafestol (73 mg/d) plus kahweol (58 mg/d) increased cholesterol by 66 mg/dl (1.7 mmol/l) after 6 weeks. Oil from Robusta beans, which contains cafestol but negligible kahweol, also raised serum cholesterol. These findings show that cafestol is at least partly responsible for the cholesterol-raising effect of boiled coffee. Coffee oils and brews containing cafestol consistently increased serum triglycerides and alanine amino-transferase, and depressed serum creatinine and gamma-glutamyl-transferase (GGT). After withdrawal GGT activity rose above baseline. Norwegians who habitually consumed 5-9 cups of boiled coffee per day had higher serum cholesterol levels and lower GGT but no higher alanine aminotransferase activity than controls. Thus, serum cholesterol is raised by cafestol and possibly also kahweol, both natural components of coffee beans. The mechanism of action is unknown but is accompanied by alterations in liver function enzymes.

[Care of the terminal cancer patient. General treatment and psychological management]

The treatment of neoplastic patients in a terminal stage causes the surgeon who takes them in charge several problems, many of which are of a psychological nature. Such problems can be summarized as concerning the psychological attitude of the patient, the relationship between the patient and his family and the relationship between the patient and the hospital. These problems, together with others more specifically linked to the nature of the neoplastic disease, are not often easy to be solved by the single physician. Therefore, we propose to set up "Multidisciplinary groups for the study of untreatable neoplastic diseases", in order to assist the surgeon in the treatment of the last stages of the disease.