From surplus bread to burger using filamentous fungi at bakeries: Techno-economical evaluation

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

Effect of viscoelasticity on foam development in zein-starch dough

Above the zein glass transition temperature (similar to 40 degrees C), the viscoelasticity of zein-starch dough is similar to that of gluten. This is of interest because this dough might be used to develop gluten-free products, although it has certain limitations such as workability and aging at room temperature. The most effective way to decrease the dough glass transition temperature is to use a plasticizer, which also influences the viscosity. In this study, viscoelastic zein-starch dough samples were prepared with several concentrations of citric acid as the plasticizer, and the effect of viscoelasticity on crumb structure formation during baking was investigated. Extensional viscosity was correlated with the average bubble size after baking. We found that viscosity could be predicted for this system by measuring the shear viscosity, whereby the Trouton ratio was near-constant for the range of plasticizer concentrations investigated. In addition, our dynamic mechanical analysis (DMA) revealed that bubble growth occurs mainly when the dough reaches 100 degrees C, due to a combination of steam formation and thermal softening of the matrix. At higher temperatures, hardening occurs due to drying and zein crosslinking. (C) 2015 Elsevier Ltd. All rights reserved

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

Filamentous ascomycetes fungi as a source of natural pigments

Abstract 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

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

Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia

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.

Effect of dispersed particles on instant coffee foam stability and rheological properties

© 2016, Springer-Verlag Berlin Heidelberg.Properties of instant coffee foam constitute the focus of this study. The coffee, obtained from commercial sources, was dispersed in water at a concentration in the range of standard use. The resulting solution contained a substantial amount of micron and submicron size particles that were filtered with membranes having difference size cut-offs in order to investigate the relationship foam properties—particles size. The foams produced from these solutions have been imaged by confocal laser scanning microscopy, and their moduli and stability have been measured by oscillatory rheology, using an in-house developed rheometric set-up. The results show that particles larger than 0.8 µm have little effect on the reduction of drainage while a clear strengthening effect on the foam was evident. This was a result of their diffusion to the lamellae borders, which increases the viscosity of the liquid–air interface. Particles smaller than 0.2 µm affect bubble coarsening and likely hinder the migration of soluble surface active species to the bubble surface. Particles also participate in the stabilization of the air–water interface, and this affects both the foam stability and mechanical properties. Established models developed for ideal foam systems containing particles are difficult to apply due to the complexity of the system studied. Despite this limitation, these results provide increased understanding of the effect of particles on instant coffee foams