The interest in mushrooms as functional ingredients has increased in the past decade. Mushrooms have low fat content and high fiber and protein contents and are natural sources of valuable food molecules such as ergosterol, polyphenols, terpene and terpenoids, and mannitol and trehalose. Mushrooms have been used as ingredients in meat- and starch-based food formulations with varying degrees of success, but their technological and functional performances in food formulations are yet to be investigated and fully explored for applications directed to the emerging alternative, meat-free, clean-label marketplace. Therefore, in this review, the current scientific data regarding the attributes of mushrooms that elicit their unique functional and nutritional properties, their relevance to the food industry, and potential opportunities for developing innovative, good-tasting, protein-rich foods from mushrooms are presented and discussed.

Mushroom by-products are economical and eco-friendly raw materials with bioactive and functional characteristics that allow for potential uses as food ingredients. However, mushroom upcycling has yet to be fully exploited, despite the many opportunities that mushrooms may offer. The mushroom protein by-product (MPBP) resulting from mushroom protein production was characterized (chemical composition, physicochemical attributes, and functional properties) and incorporated into plant-based batter formulations to prepare four experimental groups with different ratios (w/w, %) of wheat flour (W) to MPBP (100 W, 75 W/25 MPBP, 25 W/75 MPBP, and 100 MPBP). Subsequently, the batter was used for frying batter-coated shrimp, which was evaluated for cooking loss, coating pick-up, oil absorption, and color parameters (L*, a*, and b*). MPBP showed high content of dietary fiber, mainly insoluble fiber (49%), and it is potentially suited for the formulation of high-fiber food products. The MPBP physicochemical attributes pH (11.69), water activity (0.34), L* (58.56), a* (5.61), b* (18.03), and particle size distribution (250–500 µm (22.12%), 125–250 µm (41.18%), 63–125 µm (37.53%), and < 63 µm (0.82%) were noted. Concerning the MPBP functional characteristics, solubility (12.7%), emulsifying activity index (7.6 m2/gr), emulsion stability index (52.4 min), water holding capacity (4.9%), and oil holding capacity (4.8%) were reported. Adding MPBP into batter formulations for batter-coated shrimp resulted in higher values of cooking loss, oil absorption, coating pick-up, and a* color, while lowering L* and b* values. The best experimental results were reported for group 75 W/25 MPBP, which indicates that MPBP can potentially be accepted as a novel batter ingredient for partial substitution of wheat flour.