Habtamu Admassu

Valorization of fish processing waste into high‐value omega‐3 bioactive lipids represents a sustainable strategy for the development of functional foods. However, the incorporation of long‐chain polyunsaturated fatty acids (PUFAs), such as EPA and DHA, is constrained by oxidative instability, off‐flavor formation, and poor water solubility. This review critically integrates advanced encapsulation technologies with mechanistic insights into their roles in enhancing lipid stability, modulating gastrointestinal release, and improving bioavailability within diverse food matrices. Encapsulation systems not only protect PUFAs during processing and storage but also enable controlled release, thereby enhancing physiological uptake. In addition, fish oil‐derived lipids exhibit antioxidant properties through modulation of oxidative pathways and antimicrobial effects through membrane disruption and metabolic interference. A conceptual framework for the design of fortified foods is proposed, emphasizing controlled release, synergistic interactions with food components, and sustained biological functionality. By linking mechanistic understanding with practical formulation strategies, this review provides a comprehensive roadmap for the effective and safe utilization of fish waste‐derived omega‐3 lipids in next‐innovative functional foods.

The increasing demand for sustainable protein sources has accelerated the exploration of alternative systems that reduce environmental impact while maintaining nutritional value. Single‐cell protein (SCP) produced from microorganisms including bacteria, yeasts, fungi, and microalgae offers a resource‐efficient solution. Fruit processing residues (peels, pomace, and pulp) represent abundant, carbohydrate‐rich substrates suitable for microbial conversion, supporting waste valorization within a circular bio‐economy. Microbial protein content typically ranges from 30% to 55% (dry weight) under standard cultivation conditions; however, values approaching ~80% have been reported in optimized systems, particularly with selected strains and controlled fermentation environments. This variability is governed by multiple interacting factors, including substrate composition and pretreatment, carbon‐to‐nitrogen (C/N) ratio, pH, temperature, aeration, inoculum density, fermentation time, oxygen transfer, and metabolic characteristics of the microorganism. Given these interactions, Response Surface Methodology (RSM), including Box–Behnken and Central Composite designs, provides a statistically robust approach for modeling process variables and identifying optimal conditions with reduced experimental effort. Compared to one‐factor approaches, RSM enables more reliable detection of interaction effects and operational optima, although improvements are system‐dependent. Despite progress at laboratory scale, challenges remain in process scale‐up, reproducibility, energy efficiency, and techno‐economic feasibility, alongside limited integration of life‐cycle and regulatory considerations. Future work should combine statistically optimized fermentation with pilot‐scale validation and standardized reporting to support scalable and sustainable SCP production from fruit‐derived substrates.

The projected global protein deficit, expected to exceed 250 million tons by 2050, coincides with fruit‐processing residues that represent nearly 30%–40% of processed biomass, highlighting the need for integrated solutions that simultaneously address nutritional security and food‐waste valorization. This review critically synthesizes current evidence on single‐cell protein (SCP) production from fruit‐processing waste, examining how substrate composition, microbial metabolism, and downstream processing determine nutritional quality, techno‐functional performance, safety, and industrial feasibility. Reported systems consistently produce 45%–65% crude protein, with essential amino‐acid profiles comparable to soybean meal and fishmeal. Comparative analysis indicates that carbon‐to‐nitrogen ratio, pretreatment severity, oxygen transfer, and nucleic‐acid reduction strategies, rather than microorganism type alone, are the dominant factors controlling yield and composition. Techno‐functional properties, including water‐holding capacity (2.1–4.8 g/g), emulsifying activity (35%–62%), and foaming capacity (28%–55%), are strongly influenced by cell‐wall structure and protein recovery approaches, while bioactive potential is increasingly enhanced through omics‐guided strain optimization. Economic assessments identify downstream processing and biomass drying as the major cost drivers, accounting for more than 40% of total production costs, and reveal that feedstock compositional variability is the principal source of inconsistent productivity across studies. Safety evaluations highlight persistent knowledge gaps related to mycotoxin contamination, allergenicity, and acceptable nucleic‐acid levels, which currently limit regulatory acceptance despite favorable environmental outcomes demonstrated by life‐cycle analyses. Unlike earlier reviews that primarily catalog substrates and microorganisms, this work integrates nutritional, functional, safety, techno‐economic, and technological‐readiness perspectives, emphasizing the need for process integration, predictive consortium control, and standardized safety frameworks to enable the large‐scale adoption of fruit‐waste‐derived SCP in sustainable food and feed systems.

This review synthesizes recent research on strategies to address protein malnutrition in Ethiopia, where diets are predominantly maize‐based and fortification with conventional legumes is limited due to antinutritional factors, supply variability, and cost. Concurrently, fruit processing generates abundant sugar‐rich residues, including banana, mango, papaya, citrus, and pineapple wastes, which are largely underutilized yet represent attractive renewable nutrient substrates. This review presents an integrated approach to valorizing fruit waste hydrolysates for the production of single‐cell protein (SCP) powders, which can enhance the nutritional and functional quality of traditional gluten‐free Ethiopian maize flatbreads. Fruit waste hydrolysates have been reported to be rich in glucose (~228 g/L) and fructose (~55.7 g/L) and micronutrients but also contain phenolic compounds that can inhibit fermentation, necessitating controlled microbial cultivation. Food‐grade microorganisms, such as Saccharomyces cerevisiae , Candida utilis , and selected filamentous fungi, have been described to produce high protein content (often 60%–82% dry mass) and increase lysine content relative to unfortified maize flour under optimized batch and fed‐batch conditions. The resulting SCP powders have been reported to exhibit favorable technofunctional properties, including water absorption and emulsification capacity, making them suitable as dough improvers. Incorporation of 10%–15% fermented microbial protein into maize flatbreads has been reported to improve protein content (~49%–55%), enhance the amino acid profile, increase digestibility by ~40%, and preserve texture, aroma, and cultural acceptability. Although sensory changes and processing constraints remain significant challenges, with fortified, gluten‐free products often exhibiting altered texture, mouthfeel, and flavor profiles, as well as demanding precise formulation strategies to balance nutritional benefits with consumer acceptability and manufacturability, this work demonstrates a circular bioeconomy approach transforming fruit waste into high‐quality protein powders, offering a scalable, sustainable, and culturally appropriate strategy to alleviate protein deficiency. The findings provide a practical framework for introducing microbial protein into staple diets, advancing food security, and promoting efficient utilization of agroindustrial waste in low‐resource settings.

Lupine, an underutilized legume with high protein content, offers a promising plant‐based protein source for functional foods. This study evaluated four lupine genotypes to determine how extraction pH (EpH) and isoelectric precipitation pH (IEPpH) influence the techno‐functional and thermal properties of lupine protein isolates (LPIs) using response surface methodology (RSM) based on a central composite design (CCD). LPIs exhibited genotype‐dependent functional behavior: Vitabor showed the highest solubility (95.9%–95.7%) at pH 7–9 and superior foaming capacity (240%) with stability of 89.2%; the local genotype excelled in emulsifying capacity (50%) and gelation (8%), and Probor had the highest oil holding capacity (2.96 g/g). Thermal analysis revealed Sanabor possessed the highest enthalpy (Δ H = 87.36 J/g) and broad denaturation range ( T _d = 82.5°C, T _e = 122.8°C), indicating robust structural integrity, while the local genotype showed comparable thermal stability. Optimal EpH and IEPpH were genotype‐specific, reflecting inherent compositional differences affecting protein functionality and thermal behavior. Based on their distinct profiles, LPIs from Local are suitable for dairy alternatives and meat analogues, Vitabor for protein‐enriched beverages, and Probor and Sanabor for sauces, spreads, and heat‐processed foods. These findings demonstrate lupine's versatility as a functional plant protein and provide mechanistic insight into how genotype and extraction conditions govern structural and functional performance. Future studies should investigate protein digestibility, bioactive peptide formation, and application in real food and industrial systems to fully harness the nutritional and functional potential of LPIs.

Urban food waste presents a significant environmental challenge, but it also offers a promising opportunity for sustainable protein production. In Addis Ababa, it's estimated that around 70%–74% of municipal solid waste is biodegradable, with a large portion made up of fruit and vegetable residues; bananas, mangoes, avocados, and citrus fruits dominate these organic streams. These high‐moisture, nutrient‐rich materials are particularly well‐suited for single‐cell protein (SCP) production through microbial fermentation, positioning them as a climate‐resilient alternative to conventional animal or plant‐based proteins. Current research explores various aspects: substrate composition, effective pretreatment strategies, selecting optimal microbial strains, different fermentation approaches, and crucial safety issues such as nucleic acid content, allergenicity, and potential mycotoxin contamination. Globally, SCP yields range from 20 to 50 g/L, but translating these results to Addis Ababa is complicated by local variability in feedstock quality and seasonal availability. This means solutions must be tailored to the specific context. Scaling up SCP production isn't without hurdles. Major challenges include the heterogeneous nature of the feedstock, its high moisture content, limited cold‐chain infrastructure, and noticeable gaps in technical expertise. Despite these challenges, there are tangible avenues for progress: establishing pilot‐scale fermentation facilities, developing decentralized preprocessing and collection systems, and embedding these efforts within broader circular bio‐economy frameworks. Together, these strategies could enhance local protein availability, reduce landfill contributions, and help curb greenhouse gas emissions. Still, several knowledge gaps remain particularly regarding Ethiopia‐specific techno‐economic analyses, process optimization for mixed fruit waste, and capacity‐building in fermentation biotechnology. Addressing these gaps is essential for moving SCP production from the laboratory to a viable, city‐wide solution. By integrating technological, regulatory, and industrial strategies, Addis Ababa can leverage fruit‐waste valorization to address urban organic waste, strengthen nutritional security, and further Ethiopia's goals in advancing a circular bio‐economy.

The process of microencapsulation is used to coat essential oils that are vulnerable to oxidation, dampness, UV light, and high temperatures. It serves to shield the active chemicals from the environment while boosting the core material's controlled release, stability, and solubility. This work used spray and freeze‐drying procedures to microencapsulate essential oil extracted from Thymus schimperi ( T. schimperi ) leaves using hydro distillation. The objective of this study was to investigate the impact of gum Arabic as a coating agent on the physicochemical properties of T. schimperi essential oil microcapsules through spray and freeze‐drying encapsulation procedures. Water content, surface morphology, solubility, bulk density, tapped density, surface oil, flowability, particle mean diameter, and other physical and chemical properties were examined. The physico‐chemical properties of the microencapsulated samples were examined, including their releasing property, functional group identification, thermal property, and storage stability. The features of microcapsules made by spray drying differ greatly from those made by freeze drying. According to the results, spray drying was shown to have a higher encapsulation efficiency (71.05%) than freeze drying (68.89%). The solubility index of spray‐dried microcapsules was higher than that of freeze‐dried microcapsules. When compared to freeze‐dried encapsulated T. schimperi EO, the bulk density of spray‐dried encapsulated EO is lower, whereas the tapped density is reversed. Compared to freeze‐dried microcapsules, spray‐dried microcapsules had a more spherical shape.