COAST JOURNAL OF THE SCHOOL OF SCIENCE OAUSTECH OKITIPUPA

EXTRUSION BARREL TEMPERATURE EFFECT ON TEXTURAL AND PHYSICAL PROPERTIES OF READY-TO-EAT FOOD FROM CARDABA BANANA, AFRICAN YAM BEAN, AND DATES

R.T. Babalola — 2025-12-18

This work incorporated underutilized crops (cardaba banana, African yam bean, and date fruit), into composite flour used in the extrusion process of Ready-To-Eat (RTE) foods processed at two different barrel temperatures (BT) of 120 and 130 ˚C using a twin-screw extruder. Date fruit flour (DFF) served as a sweetener and binder, with a constant percentage composition for all samples. The color, texture, and physical properties of the RTEs were determined using standard procedures and equipment.

Extrusion at 120 °C BT increased the incidences of L*, a*, b*, and chroma color saturation, while BT did not affect the hue color for all RTE foods. RTEs processed at high BT had higher values of chewiness, cohesiveness, gumminess, and stringiness, as well as higher force peak values. However, no significant difference (p < 0.05) was observed for the fracturability, springiness, and hardness of all the RTEs at both BTs. Lower extrusion BT resulted in increased values of weight, diameter, density, thickness, and porosity. Nevertheless, it was observed that the values for the spread ratio and volume of the RTEs increased at higher BTs. The desired textural properties for these RTE foods were achieved at a higher BT (130 ˚C), while physical properties were affected by the composition of the composite flours used.

PROXIMATE COMPOSITION, MINERAL PROFILE AND SENSORY ANALYSIS OF RIPE AND UNRIPE Musa paradisiaca (Linn.)-FORTIFIED BREADS

S. A. Emaleku — 2025-12-18

Minerals, though required in minute quantities for proper growth and development of body tissues, contribute to the optimal functioning of the whole system. Any nutritional strategy that improves the composition, as well as, the proximate value of foods, is a desirable nutritional plan. Therefore, this study comparatively investigated the proximate composition, mineral profile and sensory attributes of ripe and unripe Musa paradisiaca (plantain)-fortified breads. Bread dough was prepared following established procedures and fortified with plantain in a ratio of 4:1. The grouping was done as follows; group A - flour bread; group B - ripe plantain-fortified bread; group C - unripe plantain-fortified bread; and Group D - ripe-unripe plantain-fortified bread. The proximate and mineral compositions of the bread samples were determined following standard protocols, while the sensory attributes were evaluated by 30 panelists. Results show that bread fortified with unripe plantain had significantly (p≤0.05) higher ash and protein contents than the other groups; although, the ash was not significantly higher than that of the ripe plantain-fortified bread. The potassium, phosphorus, calcium and sodium concentrations were also significantly higher than the other bread groups; and the iron and moisture contents were significantly different from that of ripe plantain-fortified bread. However, there was no significant difference in general acceptance between the different fortified-bread and the control bread. This study suggests fortification of bread with unripe plantain as a better nutritional strategy than fortification with ripe plantain. Food fortification with unripe plantain is recommended as a supplement for protein, iron and macro-mineral deficiencies.

Chrysophyllum albidum DETERIORATION ENTAILS DECLINE IN Pseudomonas AND INCREASE IN Acetobacter ABUNDANCE

N. G. Ogbuji — 2025-12-18

Microorganisms that inhabit fruits can affect the quality of fruits during storage. Some of these organisms are beneficial while others are deleterious (pathogenic). This paper analyzed African star apple (Chrysophyllum albidum G. Don-Holl) microbiota to detect the bacterial and fungal community structure using high-throughput sequencing (HTS) technology. Healthy and diseased fruits of C. albidum were obtained from Choba market in Port Harcourt, Rivers State, Nigeria. Bacterial and fungal DNA were extracted from the samples and subjected to 16S and 18S rRNA sequencing respectively. Metagenomic analyses of bacterial and fungal strains from the samples revealed total operational taxonomical units (OTUs) as 341 and 4366 respectively. Among bacteria, the phylum Proteobacteria was dominant while all identified fungi belong to the phylum Ascomycota. There was a significant reduction in the abundance of Pseudomonas in the diseased sample compared to the healthy sample. Conversely, relative abundance of Acetobacter increased in the diseased sample compared to the healthy sample. The fungal genera, Acidomyces, Geosmithia and Magnaporthe were also obtained. Additionally, the bacterial genera, Candidatus Portiera, Blautia, Brevibacterium, Tetragenococcus and Acinetobacter which were present in the healthy fruits were not obtained from the diseased sample. These findings can help predict microbial community structural dynamics involved in the spoilage of African star apple and thus how the spoilage can be prevented or controlled.

DEVELOPMENT OF A LOW-COST DIRECT SHEAR BOX MACHINE FOR ASSESSMENT OF SHEAR STRENGTH OF SOILS

D. A. Opeyemi — 2025-12-18

The shear strength of soils is a critical parameter in geotechnical engineering, influencing the design and stability of structures such as foundations, retaining walls, and slopes. The traditional soil testing methods face challenges related to accuracy, repeatability, and ease of operation. It is against these drawbacks that this paper presents a novel design, development, and fabrication of a direct shear box machine leveraging locally sourced materials to improve precision, user-friendliness, and reliability. A three-stage approach was adopted, which includes the design stage, the fabrication stage, and the assembly, installation, and calibration stage. At the design stage, emphasis was placed on mechanical re-engineering, innovation, automation, and validation against standard testing methods. The development phase considered the choice of tooling, ease of processing, and product quality in carrying out soil tests both in the laboratory and field with minimal stress. The fabrication phase entails the fabrication of parts and components of the designed shear box machine, while the third stage entails the assemblage, installation, and calibration of the fabricated parts and components. The developed device, when deployed for soil testing results showed a linear relationship, such that as the load increases, the deflection increases in a similar manner, and was found to be consistent with the expected statutory range with superior performance in terms of precision, accuracy, and repeatability. The developed machine cost N1,700,000.00 as against the importation price, which stood at N2,500,000.00, leading to a saving of N800,000.00. This innovative device is therefore a good substitute for traditional approaches and also a source of internally generated revenue for Olusegun Agagu University of Science and Technology, Okitipupa, Ondo State, Nigeria.