Food Composition and Nutrition Tables

Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities.

Potential Health Benefits of Olive Oil and Plant Polyphenols.

Food authenticity is presently a subject of great concern to food authorities, as the incorrect labelling of foodstuffs can represent a commercial fraud. The implication of misleading labelling can be much more important concerning the presence of potentially allergenic foods. The need to support food labelling has provided the development of analytical techniques for the analysis of food ingredients. In the last years, several methods based on polymerase chain reaction (PCR) have been proposed as useful means for identifying species of origin in foods, as well as food allergens and genetically modified organisms (GMO), due to their high specificity and sensitivity, as well as rapid processing time and low cost. This work intends to provide an updated and extensive overview on the PCR-based methods for food authentication, including also methods for allergens and GMO the detection in foods.

Food authentication by PCR-based methods

The lipid fraction of coffee is composed mainly of triacylglycerols, sterols and tocopherols, the typical components found in all common edible vegetable oils. Additionally, the so-called coffee oil contains diterpenes of the kaurene family in proportions of up to 20 % of the total lipids. Diterpenes are of interest because of their analytical and physiological effects. The composition of the main lipid components of the two most important coffee species, Coffea arabica and Coffea canphora var. Robusta is presented. In addition, the influences of typical processes like roasting and steaming on selected lipid components as well as the effects of the storage of green coffee beans under different conditions will be described. Furthermore, new findings regarding the 5-hydroxytryptamides, the main parts of the coffee wax located on the outer layer of the bean and the recently identified components coffeadiol and arabiol I will also be discussed.

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The lipid fraction of the coffee bean

https://www.dolcera.com/wiki/images/(Fernandes_&_Cabral,_2007).pdf

Phytosterols: applications and recovery methods.

Authenticity is an important issue for the food industry due to legal compliance, economic reasons (right goods for the right price), guarantee of a constant well-defined quality, use of safe ingredients (no hazardous substitutes), and religious reasons (halal, kosher). This report gives an extensive overview on the authenticity assessment of oils and fats for food products and summarizes the principal techniques useful for this assessment. Scope and limits of different analytical tools are discussed.

Authenticity assessment of fats and oils

Analysis of steryl esters in cocoa butter by on-line liquid chromatography-gas chromatography.

On-line liquid chromatography-gas chromatography (LC-GC) has been applied to the detection of vegetable oils in milk fat using β-sitosterol as marker. The method involves transesterification of the fat, pre-separation of the sterol fraction from other lipid constituents and on-line transfer to the capillary GC system. The on-line approach avoids time-consuming sample preparation steps prior to GC analysis. The suitability of this analytical approach was tested with model mixtures of milk fat with cotton and rapeseed oil. The method allows the detection of adulterations at low levels. Simultaneous quantification of cholesterol in milk fat is also possible. Considering the rapid sample preparation, the described method can be applied for screening of large sample numbers.

Rapid detection of vegetable oils in milk fat by on‐line LC‐GC analysis of β‐sitosterol as marker

An on-line LC-GC method for analysis of 16-O-methylcafestol (16-OMC) and total sterols in oils obtained from green beans of Coffea canephora (Robusta) and C. arabica (Arabica) has been developed. HPLC pre-separation of the transesterified lipids allows quantification of the content of 16-OMC. The fraction containing the sterols is transferred to on-line GC analysis. The results obtained for Arabica and Robusta samples were in good agreement with literature data obtained by classical analytical procedures. The method allows rapid and simultaneous determination of two markers (16-OMC and Δ5-avenasterol) proposed for authenticity assessment of coffee beans and overcomes time-consuming sample pretreatment steps.

Rapid and simultaneous analysis of 16-O-methylcafestol and sterols as markers for assessment of green coffee bean authenticity by on-line LC-GC

A polymerase chain reaction (PCR) was developed to differentiate the thickening agents locust bean gum (LBG) and the cheaper guar gum in finished food products Universal primers for amplification of the intergenic spacer region between trnL 3' (UAA) exon and trnF (GAA) gene in the chloroplast (cp) genome and subsequent restriction analysis were applied to differentiate guar gum and LBG The presence of <5% (w/w) guar gum powder added to LBG powder was detectable Based on data obtained from sequencing this intergenic spacer region, a second PCR method for the specific detection of guar gum DNA was also developed This assay detected guar gum powder in LBG in amounts as low as 1% (w/w) Both methods successfully detected guar gum and/or LBG in ice cream stabilizers and in foodstuffs, such as dairy products, ice cream, dry seasoning mixes, a finished roasting sauce, and a fruit jelly product, but not in products with highly degraded DNA, such as tomato ketchup and sterilized chocolate cream Both methods detected guar gum and LBG in ice cream and fresh cheese at levels <01%

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Claudia Hischenhuber

Papers

Authenticity assessment of fats and oils

Analysis of steryl esters in cocoa butter by on-line liquid chromatography-gas chromatography.

Rapid detection of vegetable oils in milk fat by on‐line LC‐GC analysis of β‐sitosterol as marker

Rapid and simultaneous analysis of 16-O-methylcafestol and sterols as markers for assessment of green coffee bean authenticity by on-line LC-GC

Determination of locust bean gum and guar gum by polymerase chain reaction and restriction fragment length polymorphism analysis.