The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2) on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass) was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production. 

The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2) on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass) was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production. 

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.

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. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

A novel approach of utilizing unsold bread at bakeries as a substrate for the fermentative production of a fungal food product have been developed. Techno-economic feasibility of implementing on-site solid-state fermentation in small-scale bakeries in Sweden to recover 10 kg/day surplus bread using the edible fungus Neurospora intermedia was investigated. Different inoculation to substrate ratios were compared, where 24% of fermented solids to inoculate the next batch presented the best fermentation-benefit ratio. Total capital cost was at its maximum €12,600 that can process 70 tons bread (10 kg/day) in its 20-years lifetime to produce 63 tons of product. Operational costs were dominated by labour cost (53%). Outcomes indicate that the process implementation is economically feasible with an annual net profit of €62,000, rate of return on investment of 18.5%, with a payback-period of 4 years at a discount rate of 7%. According to sensitivity analysis, product-selling price and process bread capacity were critical to the process's economics. Increasing the capacity to 100 kg/day resulted in a substantial increase in net profit value of €5,700,000 compared to the base case scenario. Implementation of this process cast insights on techno-economic performance of a sustainable treatment for surplus bread at bakery-level.