Journal on Processing and Energy in Agriculture

ENHANCING PEELING EFFICIENCY IN GINGER PROCESSING: A MODIFIED MECHANICAL APPROACH

Izuchukwu John OKAFOR — 2026-04-01

The growing demand for ginger in food, pharmaceutical, and cosmetic industries has exposed the limitations of manual peeling, which is labor‑intensive, time‑consuming, and prone to product loss. This study presents the design, fabrication, and evaluation of a locally sourced ginger peeling machine for small‑to‑medium scale processors. The machine was constructed using 3 mm angle iron for the frame and a galvanized steel drum (Ø410 mm × 430 mm, thickness 1.5 mm) as the peeling chamber. A 6 hp prime mover operating at 2400 rpm provided power through a bevel gear (1:1) and pulley system (1:6), driving four paddles fitted with brushes arranged 180° apart. Water was introduced at a ratio of 1:2 (ginger to water) to aid peeling and lifting action. Performance evaluation was conducted with batch sizes of 10–30 kg and peeling durations of 10–20 minutes. Parameters measured included peeling efficiency, product damage rate, throughput capacity, and labor savings. Results showed an optimum peeling efficiency of 79.4% at 20 kg batch size and 15 minutes duration, with product damage kept below 10%. Throughput capacity ranged between 60–90 kg/hr, and labor savings were significant, reducing processing time by ~75% and manpower by ~60% compared to manual peeling. The study concludes that the machine effectively bridges the gap between manual and industrial systems, offering a cost‑effective, hygienic, and efficient solution for ginger processing. Its reliance on locally available materials ensures affordability and ease of maintenance, while its performance demonstrates potential for adoption in rural and semi‑industrial contexts.

MICROCYCLONES FOR POLLEN SEPARATION FROM AIR STREAM

Andreja Živkov — 2026-04-01

The increasing concentration of airborne pollen presents significant challenges for public health and indoor air quality, resulting in development of efficient and compact separation technologies. This study focuses on the development and performance evaluation of microcyclones for the separation of pollen particles from air stream. Microcyclones utilize centrifugal forces generated by swirling airflow to separate particles based on their aerodynamic properties, offering advantages such as low maintenance, absence of filter media and continuous operation. The design methodology of the microcyclone is presented, including geometric parameters and air flow parameters selection to enhance pollen collection efficiency while minimizing pressure drop. In this study, a numerical simulation was performed to analyze the flow field prior to conducting the simulation of pollen particle separation from the air stream. The results indicated that properly designed microcyclones can achieve effective pollen removal with acceptable energy consumption, making them very suitable for different air pollutant analysis. The findings contribute to the advancement of microscale inertial separation devices for airborne allergen control.

Keywords: separation, microdevices, cyclones, microcyclone, pollen

The HYDRODYNAMICS AND MASS TRANSFER IN A VIBRATING PLATE EXTRACTION COLUMNS

Milan Sovilj — 2026-04-02

ABSTRACT

In this work experimental data available in the literature presenting the results of different studies on hydrodynamics and mass transfer in two-phase liquid-liquid (L-L) extraction columns with vibrating perforated plates (VPE) were considered. The data for different two-phase L-L systems were analyzed. The following hydrodynamic characteristics were observed: the mean drop diameter, dispersed-phase hold-up, relative velocity, and flooding velocity. The influence of operating parameters such as the agitation speed, superficial velocity of the continuous and dispersed phases, and the direction of mass transfer on the hydrodynamic characteristics of the VPE column was established. Empirical correlations for the prediction of hydrodynamic characteristics based on the data for operating parameters: column geometry, and physical properties of the fluids were presented and analyzed from the point of view of applicability. In addition, the mass transfer coefficients in VPE columns were presented and commented.

PRODUCTION AND ISOLATION OF POLYSACCHARIDES FROM MYCELIA OF NATURAL ISOLATES OF HIGHER FUNGI

Miona Miljkovic — 2026-04-03

The traditional use of higher fungi in medicine and nutrition is largely attributed to their rich content of bioactive polysaccharides. This study evaluated the ability of four fungal isolates: Ganoderma resinaceum NMKSS, Bjerkander aadusta TMF1, Fomes fomentarius TMF2and Ganoderma sp.to produce intracellular (IPS) and extracellular polysaccharides (EPS) during submerged fermentation using glucose as the carbon source. Polysaccharides were extracted from dried mycelial biomass and culture supernatants, respectively, and quantified via the phenol-sulfuric acid assay. Initial screening revealed that EPS yields ranging from 0.1 to 0.759 mg/ml and IPS yields between 0.5 and 113.3 mg/g dry biomass. Notably, B. adusta TMF1 and F. fomentarius TMF2 exhibited significantly higher polysaccharide production and were selected for further work. The influence of organic nitrogen sources on polysaccharide yield was assessed, demonstrating that peptone supplementation maximized both EPS and IPS production. F. fomentarius TMF2 achieved the highest EPS yield of 0.84 mg/mL, conversely, B. adusta TMF1 produced a maximum IPS yield of 134.12 mg/g dry biomass. Yeast extract favored biomass accumulation but was less effective in stimulating polysaccharide synthesis. These findings suggest that nitrogen source composition critically influences the balance between fungal growth and polysaccharide production. Further research is needed to optimize culture conditions and fully exploit the biotechnological potential of these isolates for food and pharmaceutical applications.

THIN-LAYER DRYING KINETICS AND COLOR CHANGES OF POTATO SLICES DURING FAR-INFRARED VACUUM DRYING

Vangelče Mitrevski — 2026-04-03

In this study far infrared vacuum drying kinetics and change of color quality parameters of potato slices were analyzed. The experimental data set of drying kinetics was obtained on the experimental set-up designed to imitate an industrial far infrared vacuum dryer. For approximation of the experimental data with regard to the moisture ratio (MR) three well known thin-layers drying models from scientific and engineering literature and model of Mitrevski et al., were used. The performed statistical analyzes show that the model of Mitrevski et al., has the best statistical performance than well-known thin-layer drying models. The estimated values of moisture diffusivity of potato slices obtained from this study are within the range from 5.14 × 10⁻⁸ to 5.01 × 10⁻⁹ m² s⁻¹. A negative effect on the total color change of far infrared vacuum dried potato slices was observed with increasing of temperature of infrared heaters and vacuum pressure.

GENDER INEQUALITY IN STEM AND RENEWABLE ENERGY EDUCATION IN UGANDA: MAKERSPACES AS PATHWAYS TO GENDER-RESPONSIVE LEARNING

Rafat Al Afif — 2026-04-13

This study examines ongoing gender inequality in Uganda’s STEM and renewable energy education pipeline, set against the backdrop of severe energy poverty and gendered burdens. It highlights the societal and innovation costs of women’s underrepresentation and explores makerspaces as inclusive, practical environments. The research aims to place girls’ and women’s STEM pathways within Uganda’s energy transition and evaluate makerspaces as a catalyst for gender-responsive learning and skills development. Using a sequential explanatory mixed-methods approach, the study incorporates: (i) a focused review; (ii) empirical fieldwork at universities and the Makerere University makerspace; and (iii) three iterative Training-of-Trainers cycles, involving surveys, interviews, focus groups, observations, and artefact reviews, alongside quantitative and qualitative analyses of inclusion and pedagogy. Results reveal deeply rooted structural barriers—such as unpaid care, labour-market discrimination, and competitive cultures—that restrict women’s participation. Well-designed makerspace training enhanced technical skills, confidence, and perceived relevance; female participation increased across training rounds, although the risk of male dominance remains without targeted measures. The study recommends coordinated, multi-level actions: adopting gender-responsive pedagogy, increasing female representation and mentorship in STEM faculties, and integrating makerspaces into supportive policies and curricula to promote scalable, gender-inclusive, hands-on learning for renewable energy careers.

VARIABILITY IN GRAIN QUALITY PARAMETERS OF WHEAT GENO-TYPES GROWN IN DIFFERENT LOCATIONS

Valentina Nikolić — 2026-04-09

Wheat is a staple food for many nations worldwide, providing essential nutrients and energy. Five local wheat cultivars were grown at four different locations in Serbia to investigate variations in grain quality. Standard laboratory procedures were used to analyze grain test weight, chemical composition, and gluten content of whole-wheat flour. The test weight of all samples ranged from 71.20 to 80.76 kg/hl, making them suitable for industrial purposes (≥73 kg/hl). However, only 65% of the samples met the quality requirement for human consumption (≥76 kg/hl), as specified by Serbian regulations on the quality of grain, mill, bakery products, and pasta. Gluten content varied from 20.9% to 43.8%. The highest starch content was found in the cultivar Aurelija from Donja Trepča (67.46% d.m.), while the highest protein content (16.04% d.m.) was observed in the cultivar Osatka from Zemun Polje. Significant differences in chemical composition, gluten content, and test weight were noted among the genotypes and across locations. The findings indicate that both genotype and location (i.e., environment) have a considerable effect on grain quality. Nevertheless, these quality parameters are considered high quality under Serbian regulations for cereal grains and products.