Stefania Marconi

Nutrients in edible mushrooms: an inter-species comparative study

A comparative study on various components of nutritional interest, such as water, protein, total amino acids, ash and minerals, in mushrooms of different species (Pleurotus ostreatus, Pleurotus eryngii, Pleurotus pulmunarius and Lentinula edodes) was carried out. Mushrooms were cultivated on the same compost (wheat straw added with 15% of sugar beet) and analysed immediately after harvest to avoid any interfering parameters. The limiting amino acid was also evaluated and the relevant protein chemical score was calculated. The moisture content of the edible mushrooms studied is high (ranging from 85.2 to 94.7%) and the ash contents range from 6.9 to 10.5% on a dry basis. Potassium is the most abundant mineral element followed by magnesium. Total nitrogen varies from 3.47 to 7.93% (dry basis), and P. ostreatus species has the largest variability among the samples analysed. The most abundant amino acids in mushrooms, expressed as percentages of total amino acids, are glutamic acid (12.8–20.9%), aspartic acid (9.1–12.1%) and arginine (3.7–11.7%), but in the analysed P. pulmunarius and L. entinus edodes a particularly low percentage of arginine (3.7 and 5.7%) has been detected. The chemical score generally ranges from 96 to 110%, the limiting amino acid being leucine or/and lysine. ©

Commercial mushrooms: nutritional quality and effect of cooking

With the aim of extending knowledge on chemical composition of mushrooms, commercial samples, widely consumed in Italy (Boletus group, Agrocybe aegerita and Pleurotus eryngii) have been examined to determine proximate composition and some components of nutritional interest such as dietary fibre, chitin, beta glucan and total phenols in raw and cooked samples. The moisture values ranged from 67.2 to 91.5 g/100 g edible weight in the raw samples, and from 71.9 to 90.4 g /100 g edible weight in the cooked samples. The lipid fraction was not relevant. Proteins, higher in Boletus group dried samples than in the other mushroom species (Agrocybe aegerita and Pleurotus eryngii), ranged from 1.5 to 7.9 g/100 g edible weight, while the ash content varied between 0.5 and 2.0 g/100 g of edible weight. Dried and re-hydrated Boletus samples showed higher levels of soluble and insoluble dietary fibre than the other samples. The amount of beta glucans varied within the same species (Boletus group samples) and represented from 2 to 13% of total dietary fibre. The chitin content ranged from 0.5 to 3.3 g/100 g edible weight. Finally, total phenols varied widely among different mushroom species, from 51.4 to 403.8 mg/100 g edible weight and from 70.4 to 301.6 mg/100 g edible weight, respectively, for raw and cooked samples.

Nutritional composition and antioxidant properties of traditional Italian dishes.

This work aims at evaluating the main nutrients (proximate, minerals), their contribution for Dietary Reference Values in Italian population, and the antioxidant properties of some popular dishes prepared in a dedicated lab-kitchen: spaghetti alle vongole, pomodori al riso, gateau di patate, carciofi alla romana, pan di Spagna. Results showed that nutrient contents and energy value varied extensively because of the variety and the nature of ingredients in the analyzed dishes, and thus defined different daily nutrient intakes and their association with health effects. A serving portion of either spaghetti alle vongole or carciofi alla romana showed to contribute to the daily nutritional recommendations respectively, with an appreciable percentage of available carbohydrates (30-22%) and a considerable content of dietary fibre (91%). Gateau di patate was particularly rich in calcium (343mg), both contributing 34% of the recommended intake, in addition to appreciable content of phosphorus and zinc. With regards to spaghetti alle vongole, pomodori al riso, gateau di patate and pan di Spagna, extractable polyphenols contributed less than 15% to total antioxidant activity, and hydrolysable polyphenols give a major contribution; carciofi alla romana showed an inverse trend. Findings provide an important contribution to the update of Italian Food Composition Databases.

Food Composition Databases: Considerations about Complex Food Matrices

Nowadays, many countries have their own national Food Composition Databases, whose continuous updating allows the inclusion of a large number of foods, reflecting the food habits of the population and the growing number of foods on the market in the best way possible. Therefore, particular attention should be directed to the study not only of individual foods or food components but also of the nutritional characteristics of dishes, meals and diets, as they are really consumed. Recently, a reviewed sensitivity in Europe towards the implementation of standardized procedures for generating reliable composition data for composite dishes has been carried out. Although direct chemical analysis is the most accurate method to determine food composition, the nutrient content of complex matrices and composite dishes is often calculated from the nutrient contents of the individual ingredients, considering the different thermal treatments and using some preparation factors. In this context, this paper aims to give an updated picture on Food Composition Databases; in particular, their application regarding complex matrices is examined together with the need to optimize their calculated nutritional values. Results obtained by this calculation should almost always be observed as approximations.

From Plant Compounds to Botanicals and Back: A Current Snapshot

This work aims at giving an updated picture of the strict interaction between main plant biologically active compounds and botanicals. The main features of the emerging class of dietary supplements, the botanicals, are highlighted. Focus is also on the definition of actual possibilities of study approach and research strategies. Examples of innovative directions are given: assessment of interaction of bioactive compounds, chemometrics and the new goal of biorefineries. Current models of existing databases, such as plant metabolic pathways, food composition, bioactive compounds, dietary supplements, and dietary markers, are described as usable tools for health research. The need for categorization of botanicals as well as for the implementation of specific and dedicated databases emerged, based on both analytical data and collected data taken from literature throughout a harmonized and standardized approach for the evaluation of an adequate dietary intake.

Food Groups and Individual Foods: Nutritional Attributes and Dietary Importance

Foods are complex objects with several attributes contributing to defining characteristics interesting for nutritional analyses. Several ways of aggregating foods are possible to describe and evaluate eating behaviors (dietary contents, adequacy, exposure, environmental impacts, etc.). The difficulty of identifying all the inherent aspects and the needs or processing large set of data has led to design of food description and food aggregation systems. These systems facilitate information comparison making feasible the whole range of elaborations using a semi-automated food matching and data linking with further dietary assessment also facilitating the design of dietary survey carried out by exploiting advanced technologies.