Edible Mushrooms: Chemical Composition and Nutritional Value

By Pavel Kalac

Edible Mushrooms provides an advanced overview of the chemical composition and nutritional properties of nearly all species of culinary mushrooms. This unique compendium gathers all current literature, which has beendispersed as fragmentary information until now.

The book is broken into five parts covering chemical and nutrient composition, taste and flavor components as well as health stimulating and potentially detrimental effects. Appendices provide helpful quick references on abbreviations, common names of mushrooms, fatty acid profiles, and an index of mushroom species. Mycologists, nutrition researchers, mushroom cultivators and distributors, and food and neutraceutical processors will benefit from this sweeping overview of edible mushrooms.

• Thoroughly explores the chemical composition and nutritional value of both cultivated and wild growing mushroom species.
• Gathers all the information available on mushroom compounds in order providing an easy comparison of nutritional properties and bioactive compounds.
• Includes hundreds of current references allowing you to further your exploration of the topic by reviewing the detailed data in the primary literature.

• Language: English
• Publisher: Academic Press
• Release date: Jan 30, 2016
• ISBN: 9780128045022

Pavel Kalac

Professor Pavel Kalac has been researching several topics of food and feed chemistry for over 40 years.He earned an MSc in Chemistry in 1965, and a PhD in Technical Sciences in 1979, both from the University of Chemistry and Technology, Prague, Czech Republic. Since 1971, he has been a member of the Faculty of Agriculture, Department of Applied Chemistry, University of South Bohemia, Ceské Budejovice, Czech Republic, where he has been professor in agricultural chemistry since 1999. Prof. Kalac’s research has focused on biologically active natural compounds, both desirable and detrimental for human health, at the interface of agriculture and food. He has published numerous articles and reviews in international journals. Expanding information particularly during the last decade encouraged him to gather knowledge in book format. His book Edible Mushrooms: Chemical Composition and Nutritional Value was published by Elsevier in 2016. In his most recent book, Effects of Forage Feeding on Milk: Bioactive Compounds and Flavor, he collates dispersed knowledge on the occurrence of several bioactive constituents in milk as affected by various forages.

Book preview

Chapter 1

Introduction

Abstract

Both cultivated and wild-growing edible mushrooms are consumed as a delicacy and for their low energy level and high fiber content. Recent global production of approximately 20 cultivated species exceeds 10 million tons. A plausible number of wild species collected and consumed in various regions of the world is unknown; however, it is probably in the order of hundreds. This book collates recent data on proteins, carbohydrates, lipids, vitamins and minerals, numerous minor components, and health-stimulating and adverse compounds of culinary mushrooms. However, the composition of toxic, inedible, and medicinal species is not included.

Keywords

Culinary mushrooms; chemical composition; nutritional value; nutrients; health stimulating components; adverse components

Contents

1.1 Basic Mycological Terms 4

References 6

Fresh and preserved mushrooms are consumed in many countries as a delicacy, particularly for their specific aroma and texture, but also for their low energy level and fiber content. However, mushrooms became a required part of nutrition during periods of staple food shortage, such as during wars. Approximately 14,000 mushroom species, described according to the rules of mycological nomenclature, represent approximately 10% of the estimated number of species existing on Earth. More than 2000 species are safe for consumption, and approximately 700 species are known to possess significant pharmacological properties (Wasser, 2002). Information on number of edible species collected for culinary purposes throughout the world varies widely between 200 and 3000. Approximately 100 species can be cultivated commercially, but only 10–20 of them can be cultivated on an industrial scale (Chang and Miles, 2004). The mushroom industry has three main segments: cultivated edible, wild-growing, and medicinal mushrooms.

According to FAOSTAT data (Table 1.1), the total world production of cultivated mushrooms was nearly 10 million tons in 2013, whereas it was only 4.2 million tons in 2000. China has been the leading producer by far. The most produced species is the Agaricus bisporus (white or button mushroom, brown mushroom, or portobello), dominating worldwide, followed by Lentinula edodes (commonly called by its Japanese name, shiitake), a species of genus Pleurotus (particularly P. ostreatus, oyster mushroom, hiratake), and Flammulina velutipes (golden needle mushroom, enokitake). Only approximately 45% of produced mushrooms are culinary-processed in the fresh form. The rest are preserved, mostly by canning and drying, with a ratio of approximately 10:1.

Table 1.1

Production statistics of cultivated edible mushrooms, including truffles, in 2013 (FAOSTAT)

Consumption of wild-growing mushrooms has been preferred to cultivated species in many countries of Central and Eastern Europe due to species diversity and more savorous properties. Moreover, mushroom picking in forests and grasslands, as a lasting part of cultural heritage, has become a highly valued recreational activity in these countries. The collection of wild mushrooms can be seen as a relic of bygone gatherers and hunters. Moreover, mushrooms in their natural habitat are regarded for their esthetic value. This attitude is quite different from that of countries where wild mushrooms have been ignored as toadstools.

Mushrooms have been collected mostly as a delicacy for the pickers’ own consumption; however, the collection has been an economic activity for some rural populations. For instance, the picking is a national hobby in the Czech Republic. Interestingly, approximately 70% of the population picks mushrooms, with a statistical mean of 5–8 kg of fresh mushrooms per household or 2–3 kg per capita yearly. Some individuals consume more than 10 kg yearly. The factual consumption is lower due to removal of parts damaged by animals or insect larvae. In Finland, approximately 42% of households were engaged in picking, with a total harvest of 15,000 metric tons in 2011. Information on the harvest of wild-growing species worldwide is lacking.

Fresh mushrooms rank among the most perishable food materials, with a very short shelf life of only 1–3 days at ambient temperature. This considerably limits their distribution and marketing. Deterioration after harvesting, such as color changes, particularly browning, weight loss, texture changes, or cap opening, is caused by high water content, high respiration rate, and lack of physical protection to avoid water loss (transpiration) and microbial attack. Various endogenous enzymes participate in biochemical changes after disruption of cellular integrity such as by mechanical damage of tissues.

Quick deterioration of mushrooms has been an obstacle for both manufacturers and consumers. Drying, canning, or deep-freezing have been traditionally used for mushroom preservation; however, emerging technologies have been studied. Gamma irradiation has been shown to be a preservation method that saves chemical parameters of various mushroom species to a greater extent than drying or freezing (Fernandes et al., 2012). Nevertheless, the period between research results and industrial application can be rather long.

The following chapters provide recent overall knowledge and include data and references since 2000. It is not possible to cite all original works. Partial reviews, when available, are thus preferentially referred to and have numerous earlier references therein. Such reviews dealing with mushroom chemical composition and nutritional value were published during the past decade (Bernaś et al., 2006; Kalač, 2009, 2012, 2013; Wang et al., 2014). Most of the available data deal with European and East Asian edible species, often called culinary mushrooms.

Many mushroom species are toxic. The inability of immobile higher fungi to escape from an attack by fungivores, ranging from insects to mammals, has led to the evolution of several defense strategies to deter the pests. Fruit bodies of fungi often produce toxins and pungent or bitter compounds to deter fungivores (for an overview see Spiteller, 2008). This book does not focus on toxic mushroom species because such information is accessible elsewhere.

Similarly, this book does not deal with medicinal species, which are widely used in East Asian folk medicine and have been recently extensively studied as potential sources of novel drugs. Commercial products from medicinal mushrooms have been obtained from large-scale cultivation of fruit bodies. However, under such conditions it is difficult to sustain a regular level of effective compounds. Therefore, the production of fungal mycelium by submerged cultivation increases. The medicinal targets are very wide; antioxidant, antitumor, antidiabetic, antimalarial, antiviral, antimicrobial, anti-Alzheimer, and hypocholesterolemic activities have been observed. The specialized International Journal of Medicinal Mushrooms has been published since 1999. Several overviews of the topic are available (eg, De Silva et al., 2013; Lindequist et al., 2005; or Wasser,