Randy Adjonu

Dr. Randy Adjonu

Charles Sturt University, Bathurst, New South Wales, Australia
orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2014 in Journal of Food Engineering
Verified
Journal Article
Closed access
RARandy Adjonu
Randy Adjonu
GDGregory Doran
Gregory Doran
PTPeter Torley
Peter Torley
SASamson Agboola
Samson Agboola

1 February 2013 in Food Chemistry
Verified
Journal Article
Closed access
RARandy Adjonu
Randy Adjonu
GDGregory Doran
Gregory Doran
PTPeter Torley
Peter Torley
SASamson Agboola
Samson Agboola

1 December 2014 in Food Hydrocolloids
Verified
Journal Article
Closed access
RARandy Adjonu
Randy Adjonu
GDGregory Doran
Gregory Doran
PTPeter Torley
Peter Torley
SASamson Agboola
Samson Agboola

16 March 2022 in Processes
Verified
Journal Article
Open access
PDF file
CFClare Louise Flakelar
Clare Louise Flakelar
RARandy Adjonu
Randy Adjonu
GDGregory Doran
Gregory Doran
JHJulia A. Howitt
Julia A. Howitt
DLDavid Luckett
David Luckett
Paul PrenzlerPaul Prenzler
Paul Prenzler
Brassica napus (canola) seed is a rich source of phytosterols, tocopherols and carotenoids, which all have recognized health benefits, although these are reduced or lost during crude oil refinement. Many studies are now outdated, so new research to monitor bioactive retention through current processing techniques is warranted. In this work, canola seed, in-process seed, and oil samples were collected from the major stages of five commercial canola oil processes. Analysis of phytosterols, tocopherols and carotenoids indicated seed pre-treatment enhanced bioactive concentrations in the crude oil. Although the bleaching step in each process eliminated all carotenoids, high concentrations of phytosterols and tocopherols remained in the refined oil across all processes, with losses notably lower than those found in previous reports. Moreover, crude oil samples from a two-stage cold pressing process showed greatly enriched concentrations of tocopherols (+122%), sterols (+140%) and carotenoids (+217%). The results show that modern Australian canola oil processing retains high phytosterol and tocopherol concentrations and warrants further investigation into bioactive enrichment strategies. Given the growing interest in health-enhanced foods, this study provides opportunities for nutrition and health-enhanced oil products and the potential for adding value in the edible oil industry.

4 February 2023 in International Journal of Food Science and Technology
Verified
Journal Article
Open access
RARandy Adjonu
Randy Adjonu
GDGregory Doran
Gregory Doran
PTPeter Torley
Peter Torley
SASamson Agboola
Samson Agboola
Summary: Whey protein hydrolysates are important food emulsifiers and bioactive ingredients. This study investigated the stability of whey protein isolate (WPI) bioactive peptide fraction nanoemulsions under representative food processing and storage conditions: pH (3–9), ion concentration (Na+, 0–200 mm and Ca2+, 0–15 mm), thermal treatment (30–90 °C) and freeze–thawing. Bioactive peptide fractions, UC–10 and UP–10, were obtained by ultrafiltration of chymotrypsin or pepsin WPI hydrolysates, respectively. The nanoemulsions produced with these fractions had droplet diameters of 177 ± 3.5 nm (UC–10) and 154 ± 1.6 nm (UP–10). Nanoemulsions destabilised at pH 3–5, around the isoelectric point of WPI proteins but were stable at higher pH values, 6–9. Nanoemulsion instability escalated above critical Na+ (25 mm) and Ca2+ (2.5 mm) concentrations, but Ca2+ accelerated droplet aggregation more strongly than Na+. Furthermore, nanoemulsions were moderately stable to heating and freeze–thawing. Overall, both WPI bioactive peptide‐stabilised nanoemulsions showed consistent stability to the processing conditions. This study expands on designing, producing and utilising nanoemulsions based on WPI bioactive peptides.

29 January 2010 in International Journal of Food Sciences and Nutrition
Verified
Journal Article
Closed access
PDF file
EAEmmanuel Ohene Afoakwa
Emmanuel Ohene Afoakwa
JKJohn Edem Kongor
John Edem Kongor
GAGeorge Amponsah Annor
George Amponsah Annor
RARandy Adjonu
Randy Adjonu
Changes in acidification and starch behaviour were investigated during co-fermentation of cassava and soybean into gari, an African fermented product. Non-volatile acidity, pH and starch content were evaluated using standard analytical methods. Starch breakdown and pasting characteristics were also analysed using a Brabender viscoamylograph. Fermentation caused significant variations in the pH, non-volatile acidity and starch concentration. The pH decreased with concomitant increases in non-volatile acidity during co-fermentation of the cassava dough. Soy fortification up to 20% caused only minimal effects on the pH, titratable acidity and starch content during the fermentation period. Starch content decreased from 69.8% to 60.4% within the 48 h fermentation time in the unfortified sample, with similar trends noted at all levels of fortification. Starch pasting characteristics showed varied trends in pasting temperature, peak viscosity, viscosity at 95°C and at 50°C-hold with increasing fermentation time and soybean concentration. Cassava could be co-fermented with soybean up to 20% concentration during gari processing without significant effect on its process and product quality characteristics.