) This is the first part of a comparison between higher plants and mushrooms from different points of view, such as taxonomy (using Jerusalem artichoke as an example of a higher plant and champignon as a mushroom), structure, nutrition, reproduction and growth. (
) This is the second part of a comparison between higher plants and mushrooms including more different points of view such as the pigments, cultivation and their nutritional/medicinal attributes.
There are also many differences between them, especially the nutrition mode, which depends on their content of pigments or chlorophyll, as well as the reproduction method, and the main structure of each one. From this point, mushrooms are fungi organisms that have no chlorophyll; thus, they cannot form their own food, but they are saprophytes (can release some enzymes to biodegrade organic matters and convert them into simple compounds to obtain their necessary foods). The main method for reproduction of mushrooms is by spores, and not all mushrooms can be cultivated like plants
[26][45][46]. Some species of both higher plants and mushrooms have nutritional and medicinal attributes, and are called medicinal plants or mushrooms. There are several kinds of mushrooms, which can in general be categorized into edible, medicinal and poisonous mushrooms, as reported by El-Ramady et al.
[47]. More dimensions for the sustainable applications of mushrooms could be found in Elsakhawy et al.
[48] and El-Ramady et al.
[49] whereas the sustainable production of medicinal plants is a great challenge, especially under the adverse conditions reported in detail by Aftab
[50].
5. Unconventional Foods of Plants and Mushrooms
There are several classifications of plants, which depend on a specific categories such as higher and lower plants based on the existence of flowers or vascular system; common and unconventional edible plants; traditional and modern wild edible plants
[51]; cultivated and wild edible plants
[52], and conventional and unconventional food plants
[53]. The common attributes that can be existed in edible mushrooms and edible plants are being consumable foods and having a nutritional value, such as desirable content of proteins, carbohydrates, or vitamins. Many studies on unconventional foods derived from plants or mushrooms have been published in different locations all over the world for plants
[53][54][55] or mushrooms
[56][57]. Increasing attention has been noticed to this group of underutilized plants, which have many different terms such as unconventional vegetables or traditional vegetables, alternative food plants, famine foods, wild edible plants, and plants for the future
[54][58]. Therefore, there is an urgent need for unconventional medicinal/food plants with consideration of their potential under the initiative of “from flask to patient” and “from field to fork”
[59].
There are many innovative technologies in food production acting as food frontiers, which can achieve eco-sustainability and the security of global food, seeking for more sustainable future. These food frontiers may include controlled-environment agriculture
[60], climate-driven northern agricultural expansion
[61], cellular agriculture
[62], entomophagy
[63] and seaweed aquaculture
[3][64][65]. Based on the single-cell protein in macro-fungi/mushrooms, many possibilities exist to use agricultural residues and wastes because of their fast growth, high cell densities, long history of use, and simple reactor design. However, they have many challenges, including a need for non-food carbon substrates and a possibility for existing mycotoxins
[62]. The main target that attracts several scientists all over the world is how to find “plant protein-based meat and dairy analogues” especially under climate change
[66][67][68], and single-cell proteins derived from mushrooms as reported by Stephan et al.
[69] in
Table 1. Mushrooms contain many bioactive compounds (e.g., phenolics, polysaccharides, polyketides, steroids, triterpenoids, etc.), are considered nutraceuticals, a vegan protein source (up to 45%), and food flavor agents for the food industry
[70]. The protein content in mushrooms depends mainly on the mushroom species and the edible part of the mushroom (i.e., fruiting body and mycelium), where the most common mushrooms
Pleurotus ostreatus, Agaricus biosporus, and
Lentinus edodes (Berg) have protein (%) in fruiting body and mycelium as follows (36 and 25.70), (45.9 and 47.1), and (23.5 and 17%), respectively in fruiting body and mycelium
[70].
Table 1. Some examples of plant protein-based meat and dairy analogues and their sources.
On the other hand, many plants are considered plant-based foods that are rich in their content of proteins such as legumes, grains (mainly quinoa), nuts, and certain fruits like apricots, avocados, guavas, peaches, and raspberries
[67]. Quinoa, as a pseudo-cereal crop, is considered important protein crop because of its amino acidic profile, gluten-free, high antioxidant content, bioactive properties, high nutrient content (i.e., Ca, P, B, Fe, K, Mg) and vitamins like B1, B2, B3, B6, and E
[67]. Quinoa can also be used as an alternative for vegan diets, including in quinoa-based gels
[80][81], quinoa protein isolates
[82][83], to produce high-quality protein and low-cost enriched pasta
[84], and quinoa protein fortification
[85].