Jiri Mlcek

Beta-glucans in higher fungi and their health effects

Together with chitin, the beta-glucans are components of mycetes cell walls. A high level of biological efficiency has been found in beta-glucans, especially beta-1,3-D-glucans and beta-1,6-D-glucans isolated from some basidiomycetes. (Biological efficiency refers to the relative ability of beta-glucans to promote a desired response, for example to induce leukocyte activation and to produce inflammatory mediators.) These polysaccharides increase the number of Th1 lymphocytes, which help protect organisms against allergic reactions. A number of beta-glucans, for example pleuran from Oyster (Pleurotus spp.) mushrooms or lentinan from Shiitake (Lentinus edodes) mushrooms, have shown marked anticarcinogenic activity. In addition to having an immunity-stimulating effect, beta-glucans may participate in physiological processes related to the metabolism of fats in the human body. Their application results in a decrease in the total cholesterol content in blood and may also contribute to reductions in body weight.

Bioactive Compounds and Antioxidant Activity in Different Types of Berries

Berries, especially members of several families, such as Rosaceae (strawberry, raspberry, blackberry), and Ericaceae (blueberry, cranberry), belong to the best dietary sources of bioactive compounds (BAC). They have delicious taste and flavor, have economic importance, and because of the antioxidant properties of BAC, they are of great interest also for nutritionists and food technologists due to the opportunity to use BAC as functional foods ingredients. The bioactive compounds in berries contain mainly phenolic compounds (phenolic acids, flavonoids, such as anthocyanins and flavonols, and tannins) and ascorbic acid. These compounds, either individually or combined, are responsible for various health benefits of berries, such as prevention of inflammation disorders, cardiovascular diseases, or protective effects to lower the risk of various cancers. In this review bioactive compounds of commonly consumed berries are described, as well as the factors influencing their antioxidant capacity and their health benefits.

Fatty Acids Composition of Vegetable Oils and Its Contribution to Dietary Energy Intake and Dependence of Cardiovascular Mortality on Dietary Intake of Fatty Acids

Characterizations of fatty acids composition in % of total methylester of fatty acids (FAMEs) of fourteen vegetable oils—safflower, grape, silybum marianum, hemp, sunflower, wheat germ, pumpkin seed, sesame, rice bran, almond, rapeseed, peanut, olive, and coconut oil—were obtained by using gas chromatography (GC). Saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), palmitic acid (C16:0; 4.6%–20.0%), oleic acid (C18:1; 6.2%–71.1%) and linoleic acid (C18:2; 1.6%–79%), respectively, were found predominant. The nutritional aspect of analyzed oils was evaluated by determination of the energy contribution of SFAs (19.4%–695.7% ERDI), PUFAs (10.6%–786.8% ERDI), n-3 FAs (4.4%–117.1% ERDI) and n-6 FAs (1.8%–959.2% ERDI), expressed in % ERDI of 1 g oil to energy recommended dietary intakes (ERDI) for total fat (ERDI—37.7 kJ/g). The significant relationship between the reported data of total fat, SFAs, MUFAs and PUFAs intakes (% ERDI) for adults and mortality caused by coronary heart diseases (CHD) and cardiovascular diseases (CVD) in twelve countries has not been confirmed by Spearman’s correlations.

Phenolic Profile of Edible Honeysuckle Berries (Genus Lonicera) and Their Biological Effects

The current status of research on polyphenolic compounds in the berries of edible honeysuckle and their biological effects, including recommended utilization, are reviewed. The major classes of phenolic compounds in the blue berried honeysuckle are flavonols (quercetin, rutin, quercitrin) and flavanes (proanthocyanidins, catechins) and anthocyanins. Cyanidin-3-glucoside and cyanidin-3-rutinoside are considered as major anthocyanidins in edible honeysuckle berries. Such a high level of antioxidant activity in the berries of different species of the genus Lonicera is especially due to the high level of polyphenolic compounds, especially anthocyanins. These berries seem to be prospective sources of health-supporting phytochemicals that exhibit beneficial anti-adherence and chemo-protective activities, thus they may provide protection against a number of chronic conditions, e.g., cancer, diabetes mellitus, tumour growth or cardiovascular and neurodegenerative diseases.

Edible Flowers—A New Promising Source of Mineral Elements in Human Nutrition

On a global scale, people are demanding more attractive and tasty food. Both the quality of foodstuffs and aesthetic aspects contribute to the appearance of consumed meals. The attraction and appeal of individual dishes could be enhanced by edible flowers. New information concerning the composition and nutritional value of edible flowers is also important and represents a sufficient reason for their consumption. The aim of this study is to contribute to the popularization of some selected edible flowers of ornamental plants involving altogether 12 species. The flowers were used to determine their antioxidant capacity, which fluctuated between 4.21 and 6.96 g of ascorbic acid equivalents (AAE)/kg of fresh mass (FM). Correlation coefficients between antioxidant capacity and the contents of total phenolics and flavonoids were r2 = 0.9705 and r2 = 0.7861, respectively. Moreover, the results were supplemented with new data about the mineral composition of edible flowers (mostly, not found in the available literature). The highest levels of mineral elements were observed in the flowers of species Chrysanthemum, Dianthus or Viola. The most abundant element was potassium, the content of which ranged from 1,842.61 to 3,964.84 mg/kg of FM.

Selected cultivars of cornelian cherry (Cornus mas L.) as a new food source for human nutrition

The aim of this work was to determine antioxidant activity in 12 cultivars of cornelian cherry (Cornus mas L.). Two assays based on ion reduction of ABTS (2,2´-azinobis(3-ethylbenzothiazoline-6sulphonate) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals were used for antioxidant activity. Total phenolic content of the fruit was analysed by Folin-Ciocelteau colorimetric method and ascorbic acid content was analysed using column chromatography - electrochemical detector (Coulochem III). The

Polyphenolic Profile and Biological Activity of Chinese Hawthorn (Crataegus pinnatifida BUNGE) Fruits

Chinese hawthorn (Crataegus pinnatifida Bge.) fruits are rich in polyphenols (e.g., epicatechin, procyanidin B2, procyanidin B5, procyanidin C1, hyperoside, isoquercitrin and chlorogenic acid)—active compounds that exert beneficial effects. This review summarizes all information available on polyphenolic content and methods for their quantification in Chinese hawthorn berries and the relationships between individual polyphenolic compounds as well. The influence of species or cultivars, the locality of cultivation, the stage of maturity, and extract preparation conditions on the polyphenolic content were discussed as well. Currently, only fruits of C. pinnatifida and C. pinnatifida var. major are included in the Chinese Pharmacopoeia. Recent trials have demonstrated the efficacy of Chinese hawthorn fruit in lowering blood cholesterol and the risk of cardiovascular diseases. The fruit has also demonstrated anti-inflammatory and anti-tumour activities. This review deals mainly with the biological activity of the fruit related to its antioxidant properties.

Phenolic content and antioxidant capacity in algal food products

The study objective was to investigate total phenolic content using Folin-Ciocalteu’s method, to assess nine phenols by HPLC, to determine antioxidant capacity of the water soluble compounds (ACW) by a photochemiluminescence method, and to calculate the correlation coefficients in commercial algal food products from brown (Laminaria japonica, Eisenia bicyclis, Hizikia fusiformis, Undaria pinnatifida) and red (Porphyra tenera, Palmaria palmata) seaweed, green freshwater algae (Chlorella pyrenoidosa), and cyanobacteria (Spirulina platensis). HPLC analysis showed that the most abundant phenolic compound was epicatechin. From spectrophotometry and ACW determination it was evident that brown seaweed Eisenia bicyclis was the sample with the highest phenolic and ACW values (193 mg·g−1 GAE; 7.53 µmol AA·g−1, respectively). A linear relationship existed between ACW and phenolic contents (r = 0.99). Some algal products seem to be promising functional foods rich in polyphenols.

A Comprehensive Look at the Possibilities of Edible Insects as Food in Europe – a Review

Abstract Possibilities of edible insects use in European countries, are now an increasingly debated issue. Insects in Asian, African, Central American and South Central American cultures are mainly nutritional components. This review mainly describes the species of insects that are suitable as food in Europe and other developed countries. This comprehensive work addresses the issue of eating insects, especially considering the nutritionally important factors. Risks are also mentioned, as well as allergies, toxicity, and other aspects of the breeding and use of edible insects. Insects play and will play important roles in the future in various fields of research, exploitation, breeding, etc. This review provides a comprehensive current and future view of insects as a valuable foodstuff.

Total phenolics, flavonoids, antioxidant activity, crude fibre and digestibility in non-traditional wheat flakes and muesli

The five different types of muesli composed of non-traditional wheat flakes were prepared and analysed. Dickkopf wheat, red wheat, kamut and spelt were compared with commercial wheat flakes. Wheat flakes and muesli were assessed for basic analyses (dry matter, ash, protein, starch and fat content), total phenolic and flavonoid content, antioxidant activity (ABTS and DPPH assays), crude fibre content and in vitro digestibility. Furthermore, sensory evaluation of muesli involving scale and ranking preference tests was provided. Flakes and muesli made from Dickkopf wheat and red wheat showed the highest total phenolic and flavonoid content and, consequently, the highest antioxidant activity. Moreover, these cereals were high in crude fibre and thus were less digestible. On the other hand, the lowest total phenolic and flavonoid contents and antioxidant activity were determined in commercial flakes and muesli produced from these flakes. The flakes made from non-traditional wheat were sensorially comparable to commercial products.