Development of Meat Substitutes from Filamentous Fungi Cultivated on Residual Water of Tempeh Factories.

In recent years, there has been an increased motivation to reduce meat consumption globally due to environmental and health concerns, which has driven the development of meat substitutes. Filamentous fungal biomass, commonly known as mycoprotein, is a potential meat substitute since it is nutritious and has filaments to mimic meat fibrils. The current study aimed to investigate the potential use of a cheap substrate derived from the food industry, i.e., residual water in a tempeh factory, for mycoprotein production. The type of residual water, nutrient supplementation, optimum conditions for biomass production, and characteristics of the mycoprotein were determined. The results showed that the residual water from the first boiling with yeast extract addition gave the highest mycoprotein content. The optimum growth condition was a pH of 4.5 and agitation of 125 rpm, and it resulted in 7.76 g/L biomass. The mycoprotein contains 19.44% (w/w) protein with a high crude fiber content of 8.51% (w/w) and a low fat content of 1.56% (w/w). In addition, the amino acid and fatty acid contents are dominated by glutamic acid and polyunsaturated fatty acids, which are associated with an umami taste and are considered healthier foods. The current work reveals that the residual boiling water from the tempeh factory can be used to produce high-quality mycoprotein.

Fungi Burger from Stale Bread? A Case Study on Perceptions of a Novel Protein-Rich Food Product Made from an Edible Fungus.

The current study aims to assess how a novel fungi product made from the filamentous fungus Neurospora intermedia, cultivated on bread residuals, is perceived using questionnaires. Participants were asked to rate characteristic attributes of a fungi burger patty and state their preference when comparing it to Quorn and hamburger patties. The data were analyzed to assess whether gender or age was statistically associated with preference profiles. Neither age nor gender was associated with the preference profiles regarding the comparison of burger patties. Except for age and bitterness, age and gender were also not associated with the preference profiles regarding the sensory characteristics of the fungi burger patty. Most of the participants liked the characteristics of the fungi burger patty. The results indicate that fungi products from waste can become accepted products when information dissemination targets environmental benefits. Moreover, to be commercially accepted, the chewiness and bitterness of the product should be improved. Other improvements should target the overall taste in order to cater to people who prefer meat-based protein sources.

From stale bread and brewers spent grain to a new food source using edible filamentous fungi.

By-products from the food sector with a high load of organic matter present both a waste-handling problem related to expenses and to the environment, yet also an opportunity. This study aims to increase the value of stale bread and brewers spent grain (BSG) by re-introducing these residues to the food production chain by converting them to new protein-enriched products using the edible filamentous fungi Neurospora intermedia and Rhizopusoryzae. After 6 days of solid state fermentation (at 35°C, with a95% relative humidity and moisture content of 40% in the substrate) on stale bread, a nutrient-rich fungal-fermented product was produced. The total protein content, as analyzed by total amino acids, increased from 16.5% in stale sourdough bread to 21.1% (on dry weight basis) in the final product with an improved relative ratio of essential amino acids. An increase in dietary fiber, minerals (Cu, Fe, Zn) and vitamin E, as well as an addition of vitamin D2 (0.89 µg/g dry weight sample) was obtained compared with untreated stale bread. Furthermore, addition of BSG to the sourdough bread with the aim to improve textural changes after fermentation showed promising outcomes. Cultivation of N. intermedia or R. oryzae on stale sourdough bread mixed with 6.5% or 11.8% BSG, respectively, resulted in fungal-fermented products with similar textural properties to a commercial soybean burger. Bioconversion of stale bread and BSG by fungal solid state fermentation to produce a nutrient-enriched food product was confirmed to be a successful way to minimize food waste and protein shortage.

Combining submerged and solid state fermentation to convert waste bread into protein and pigment using the edible filamentous fungus N. intermedia.

Waste streams from ethanol and bread production present inexpensive, abundant and underutilized renewable substrates that are highly available for valorisation into high-value products. A combined submerged to solid state fermentation strategy was studied using the edible filamentous fungus Neurospora intermedia to biotransform ethanol plant residues 'thin stillage' and waste bread as substrates for the production of additional ethanol, biomass and a feed product rich in pigment. The fungus was able to degrade the stillage during submerged fermentation, producing 81 kg ethanol and 65 kg fungal biomass per ton dry weight of thin stillage. Concurrently, the second solid state fermentation step increased the protein content in waste bread by 161%. Additionally, 1.2 kg pigment per ton waste bread was obtained at the best conditions (6 days solid state fermentation under light at 95% relative humidity at 35 °C with an initial substrate moisture content of 40% using washed fungal biomass to initiate fermentation). This study presents a means of increasing the value of waste bread while reducing the treatment load on thin stillage in ethanol plants.

Post-treatment of Fungal Biomass to Enhance Pigment Production.

A new post-treatment method of fungal biomass after fermentation is revealed. The post-treatment strategy was utilized to produce pigments as an additional valuable metabolite. Post-treatment included incubation at 95% relative humidity where the effects of harvesting time, light, and temperature were studied. Pigment-producing edible filamentous fungus Neurospora intermedia cultivated on ethanol plant residuals produced 4 g/L ethanol and 5 g/L fungal biomass. Harvesting the pale biomass after 48 h submerged cultivation compared to 24 h or 72 h increased pigmentation in the post-treatment step with 35% and 48%, respectively. The highest pigment content produced, 1.4 mg/g dry fungal biomass, was obtained from washed biomass treated in light at 35 °C whereof the major impact on pigmentation was from washed biomass. Moreover, post-treated biomass contained 50% (w/w) crude protein. The post-treatment strategy successfully adds pigments to pre-obtained biomass. The pigmented fungal biomass can be considered for animal feed applications for domestic animals.

Does the second messenger cAMP have a more complex role in controlling filamentous fungal morphology and metabolite production?

The effect of second messenger cAMP on the physiological aspects of fungal cells such as pigmentation has been reported previously. However, their actual role in the cellular biochemical cascade that eventually affects the fungal growth morphology, such as mycelial pellet formation, is unclear. This article intends to open up the detailed study on the possible correlative effect of cAMP on the morphological and physiological growth aspects of filamentous fungi, with special emphasis on the industrial metabolite production.

Filamentous ascomycetes fungi as a source of natural pigments.

Filamentous fungi, including the ascomycetes Monascus, Fusarium, Penicillium and Neurospora, are being explored as novel sources of natural pigments with biological functionality for food, feed and cosmetic applications. Such edible fungi can be used in biorefineries for the production of ethanol, animal feed and pigments from waste sources. The present review gathers insights on fungal pigment production covering biosynthetic pathways and stimulatory factors (oxidative stress, light, pH, nitrogen and carbon sources, temperature, co-factors, surfactants, oxygen, tricarboxylic acid intermediates and morphology) in addition to pigment extraction, analysis and identification methods. Pigmentation is commonly regarded as the output of secondary protective mechanisms against oxidative stress and light. Although several studies have examined pigmentation in Monascus spp., research gaps exist in the investigation of interactions among factors as well as process development on larger scales under submerged and solid-state fermentation. Currently, research on pigmentation in Neurospora spp. is at its infancy, but the increasing interest for biorefineries shows potential for booming research in this area.