Dominic Agyei

University of Otago · Department of Food Science

The nutritional value of oats can be enhanced through solid‐state fermentation (SSF) to release otherwise tightly bound, inaccessible nutrients and bioactives. Extensive research has shown that SSF can liberate bioactive compounds from oats, such as phenolic compounds and peptides through modification of the microstructure. Studies also demonstrate...

Plant proteins are increasingly incorporated into food products to enhance their nutritional value. However, little is known about how this alters the textural perceptions of such products. This study investigated the substitution of up to 35% wheat flour with pea protein isolate (PPI) into pasta sheets to determine how this influenced texture. Fur...

Background Civet coffee is produced from coffee beans that have been consumed and excreted by civets. However, its production raises several ethical concerns. The increasing cases of adulteration create significant challenges in verifying the authenticity of civet coffee. Currently, there is no comprehensive review addressing alternative and sustai...

Food quality and freshness deterioration are global concerns during the packaging, distribution, and storage of perishable food items such as fish, meat, seafood, milk, fruits, and vegetables. Using smart packaging films to monitor food freshness biomarkers in real time can assist customers in making purchasing decisions. Recently, interest has ris...

The food and beverage industry worldwide is trying to switch to using environment-friendly and bio-degradable materials in food packaging to avoid environmental concerns of using petroleum-derived plastic (synthetic polymers) materials. In this study, chitosan (CH) hydrogel films were fabricated by using its derivative chitooligosaccharides (COS) a...

Foods that are produced and processed locally using some forms of traditional knowledge are important for achieving food and nutrition security in Africa. These food crops are generally nutritious, being rich in essential nutrients and bioactive food compounds necessary for health promotion. Additionally, most African indigenous food crops are bett...

Lipopeptides are a class of lipid–peptide‐conjugated compounds with differing structural features. This structural diversity is responsible for their diverse range of biological properties, including antimicrobial, antioxidant, and anti‐inflammatory activities. Lipopeptides have been attracting the attention of food scientists due to their potentia...

Chicken egg white (EW) proteins possess various useful techno-functionalities, including foaming, gelling or coagulating, and emulsifying. The gelling property is one of the most important functionalities of EW proteins, affecting their versatile applications in the food and pharmaceutical industries. However, it is challenging to develop high-qual...

Surfactants, also known as surface-active agents, have emerged as an important class of compounds with a wide range of applications. However, the use of chemical-derived surfactants must be restricted due to their potential adverse impact on the ecosystem and the health of human and other living organisms. In the past few years, there has been a gr...

This review explores Prionoplus reticularis, an indigenous New Zealand edible insect, commonly known as the 'Huhu grub'. With a rich history of consumption by Māori and a presence in local food festivals, Huhu grubs are gaining attention as a potential alternative protein source. Growing global populations increase the demand for nutrient-rich food...

Plant-based foods are being increasingly favored to feed the ever-growing population, but these need to exhibit improved nutritional value in terms of protein quality and digestibility to be considered a useful alternative to animal-based foods. Germination is essential for plant growth and represents a viable method through which the protein quali...

Due to the current growing interest in the search for alternative sources of protein and bioactive peptides for food and pharmaceutical applications, various seeds have been exploited. Chia (Salvia hispanica), an herbaceous annual plant, contains seeds overwhelmed with polyunsaturated fatty acids, carbohydrates, proteins, dietary fiber, minerals, a...

This study evaluated the effect of high-speed homogenisation (HSH), combined with pH adjustment, on the extraction of proteins from Arthrospira platensis and the in vitro protein digestibility of the treated microalgal biomass. Combining HSH and pH treatment effectively disrupted A. platensis cells and enhanced protein extraction. Optimum condition...

Biosensors are analytical devices for detecting a wide range of targets, including cells, proteins, DNA, enzymes, and chemical and biological compounds. They mostly rely on using bioprobes with a high binding affinity to the target for specific detection. However, low specificity and effectiveness of the conventional biosensors has led to the searc...

The giant freshwater prawn (Macrobrachium rosenbergii) is a high-yielding prawn variety well-received worldwide due to its ability to adapt to freshwater culture systems. Macrobrachium rosenbergii is an alternative to shrimp typically obtained from marine and brackish aquaculture systems. However, the use of intensive culture systems can lead to di...

Food fermentation using lactic acid bacteria (LAB) is an ancient technique that has been deemed a simple and economical way to modify nutritional contents of plant-based foods. In many cultures, this practice shows a long history with a wide variety of fermented liquid and semi-liquid traditional foods being produced from cereals, legumes, and tube...

Aside from their bioremediation roles, little is known about the food and feed value of earthworms. In this study, a comprehensive evaluation of the nutritional composition (proximate analysis and profiles of fatty acids and minerals) and techno-functional properties (foaming and emulsion stability and capacity) of earthworm (Eisenia andrei, source...

Meat is a popular animal-based food globally, but it is highly sensitive to deterioration during storage due to high nutrient content. Thus, different preservation methods have been applied to preserve the meat and meat products in certain desirable periods. However, most packaging technology in commercial markets is developed from petroleum and sy...

In the past, people used to preserve perishable food products, such as fish and oil, by utilizing their indigenous knowledge or technology. Due to consumer demand and the transportation of perishable foods from one country to another, different types of technology have been created to preserve food. The existing technologies for food preservation i...

Fish poisoning (FP) affects human health, trade and livelihood in Fiji, where management has depended mainly on traditional ecological knowledge (TEK). This paper investigated and documented this TEK through a 2-day stakeholder workshop, group consultation, in-depth interviews, field observations, and analyses of survey data from the Ministry of Fi...

The amino acid profile, techno-functionalities (foaming stability/capacity, emulsion sta- bility/capacity, solubility, and coagulation), and physicochemical characteristics (colour, particle size, surface hydrophobicity, Fourier-transform infrared spectroscopy, and differential scanning calorimetry) of protein extracts (PE) obtained from Prionoplus...

A comprehensive evaluation of the fatty acid and mineral composition of Rhynchophorus ferrugineus (sago grub powder, SGP), pre-treated to meet New Zealand import biosecurity requirements, was investigated. Palmitic acid (42.5% FA), oleic acid (39.0% FA), and linoleic acid (1.02% FA) were the most abundant saturated fatty acid, monounsaturated fatty...

Worldwide, consumers are demanding safe foods that are minimally processed and retain quality and health properties. Achieving these requirements calls for the development of effective food packaging materials. The challenge is that plastic polymers and synthetic preservatives are not suitable for developing active food packaging due to their harmf...

The objective of this study was to evaluate the effect of pulsed electric fields (PEF) on the in vitro starch digestibility properties of oat flour. A wide range of PEF process intensity was investigated (electric field strength between 2.1 and 4.5 kV/cm and specific energy inputs between 52 and 438 kJ/kg using 20 μs square wave bipolar pulse at 10...

The drug-likeness and pharmacokinetic properties of 23 dairy-protein-derived opioid peptides were studied using SwissADME and ADMETlab in silico tools. All the opioid peptides had poor drug-like properties based on violations of Lipinski’s rule-of-five. Moreover, prediction of their pharmacokinetic properties showed that the peptides had poor intes...

Edible insects have huge potential as an important alternative food and feed, and research in this area has developed considerably over the past few decades. In this study, a bibliometric analysis was conducted for the first time to provide a quantitative and visualization analysis of the trends in the edible insect research landscape. Documents on...

Traditional food fermentation is a practice that precedes human history. Acidic products such as yogurts and sourdoughs or alcoholic beverages produced through lactic acid or yeast fermentations, respectively, are widely described and documented. However, a relatively less popular group of fermented products known as alkaline fermented foods are co...

The fatty acid (FA) profile, nutritional index, and thermal properties of lipids from Tenebrio molitor and Hermetia illucens larvae were studied. T. molitor and H. illucens larvae had high lipid contents (respectively 28.8% and 42.6%), saturated (25.0% and 55.8%), monounsaturated (MUFA) (39.2% and 28.3%), and polyunsaturated (PUFA) fatty acids (35....

The proximate composition, fatty acid profile, and lipid nutritional indices of the edible Huhu grub development stages (small, medium, large larvae, and pupae) of the New Zealand endemic beetle (Prionoplus reticularis), were investigated. Ash (1.5 - 3.2%, dry weight (DW)) and crude protein (26.2 – 30.5%, DW) contents were similar across the develo...

Background Rice is a staple food globally and plays a key role in the food system of many countries in the world. However, rice is prone to contamination by mycotoxins such as aflatoxins, fumonisins, ochratoxins, deoxynivalenol, zearalenone, citrinin, sterigmatocystin, cyclopiazonic acid, patulin, gliotoxin and trichothecenes. These mycotoxins are...

Prionoplus reticularis larvae (‘Huhu grubs’), a traditional food in New Zealand, have been grown commercially. However, no information is available on the composition or safety of the larvae as a food. A proximate analysis (58.7–75.2% moisture, 26.2–30.5% protein, 32.1–58.4% fat, and 1.5–3.2% ash dry weight basis) found that Huhu grubs contain subs...

Assessment of food quality is an important feature in novel food products development process. This is because quality has implications for safety, nutritional contents, traceability, and market value of foods. However, due to the biochemical complexities of food products, it has become important that advanced analytical tools relating to proteomic...

Nowadays, consumer interest in the microbial safety of food products, desirable flavor, high nutritional profile, and extended shelf life is increasing. This trend has prompted the research and development of novel food processing technologies to promote safety and increase shelf life while minimizing the loss of flavor and nutrients. Fish roe and...

Evaluations have been made about the physicochemical stability in water-in-oil-in-water (W/O/W) emulsion loaded with resveratrol under different pH, NaCl concentration, temperature, and storage time. The in vitro digestion and Caco-2 cell transport were also investigated. Results showed W/O/W emulsion remained stable at pH 2–8, temperatures of 25–7...

Due to the rapid growth in the global population, the consumption of animal-based food products/food compounds has been associated with negative implications for food sustainability/security. As a result, there is an increasing demand for the development of plant-based food and compounds as alternatives. Meanwhile, a growing number of studies repor...

The current research aimed to investigate the effect of pulsed electric fields (1 kV/cm; 50 and 150 kJ/kg) followed by blanching (3 min., 100 °C) on the colour development of potato slices during frying on a kinetic basis. Four potato cultivars ‘Crop77’, ‘Moonlight’, ‘Nadine’, and ‘Russet Burbank’ with different content of glucose and amino acids w...

Tenebrio molitor (mealworms) and Hermetia illucens (Black soldier fly) larvae were analysed for the effect of feed composition on the fatty acid profiles. The larvae were raised on various feeds to which the basal diet had been supplemented to various levels with seed meals (flax seed, chia seed, hemp seed, and rapeseed). Fatty acid classes and com...

Crude β-D-galactosidase from Lactobacillus leichmannii 313 was used to synthesise galacto-oligosaccharides (GOS) from lactose. Using an initial lactose concentration of 170 g/L, the yield of GOS was 52 g/L (i.e. 62% lactose conversion) after 2 h of enzymatic reaction. The highest number of unique individual GOS were generated after 48 h of reaction...

Being the most widely cultivated and consumed plant food, cereals have been known to humans since ancient times. The rich nutritional profile of cereals, namely, vitamins, minerals, dietary fiber, proteins, lipids, and carbohydrates; together with the abundance of certain secondary metabolites makes cereals an excellent source of high value nutrace...

Diabetes mellitus, particularly type 2 diabetes, is a major global health issue, the prevalence of which seems to be on the rise worldwide. Interventions such as healthy diet, physical activity, maintaining a healthy weight, and medication (for those with a diagnosis of diabetes) are among the most effective strategies to prevent and control diabet...

Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell‐envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB...

In this study, the physicochemical properties, pharmacokinetics properties, and drug-likeness of pigments from Monascus-fermented rice (Monascus pigments, MPs) were predicted in silico using SwissADME tool. In silico prediction of physicochemical properties showed that MPs had desirable lipophilic drug-like physicochemical properties including mole...

Microorganisms from extreme environments tend to undergo various adaptations due to environmental conditions such as extreme pH, temperature, salinity, heavy metals, and solvents. Thus, they produce enzymes with unique properties and high specificity, making them useful industrially, particularly in the food industries. Despite these enzymes' remar...

β-galactosidases from Lactobacillus leichmannii 313 (LL 313) were immobilized for the first time by cross-linked enzyme aggregates (CLEA) technology. By using three precipitants (saturated ammonium sulfate (ASF), acetone (ACT), and isopropanol (IPA) in CLEA preparation and assessing performance in comparison with crude enzyme, recovered activities...

This research aimed to investigate the physicochemical properties of thermally processed oat flour (TPOF) “fractions” (Supernatant, Top/S1, Middle/S2, Bottom/S3) after Pulsed Electric Fields (PEF) treatment of TPOF at 2 and 4 kV/cm between 50 and 451 kJ/kg. Supernatant from PEF-treated TPOF displayed a generally higher β-glucan content than untreat...

In Africa, milk production, processing and consumption are integral part of traditional food supply, with dairy products being a staple component of recommended healthy diets. This review provides an overview of the microbial safety characteristics of milk production and fermented dairy products in Africa. The object is to highlight the main microb...

The food and health applications of bioactive peptides have grown remarkably in the past few decades. Current elucidations have shown that bioactive peptides have unique structural arrangement of amino acids, conferring distinct functionalities, and molecular affinity characteristics. However, whereas interest in the biological potency of bioactive...

In this study, hypotensive peptides derived from mature flaxseed protein sequences were predicted in silico using BIOPEP-UWM with nine proteases, three each from digestive, plant and microbial sources. The physicochemical properties of 2256 ACE-inhibitory peptides and 267 renin-inhibitory peptides (including seven (7) peptides with dual inhibitory...

The endoenzyme β-galactosidase (β-d-galactoside galactohydrolase; EC 3.2.1.23) has been used at industrial scales for the preparation of lactose-free milk and for the conversion of lactose to galacto-oligosaccharides (GOS) prebiotics. In this study, using Plackett–Burman (PB) design and the response surface methodology (RSM), the batch growth condi...

glucan is a strongly hydrophilic non-starchy polysaccharide, which, when incorporated in food, is renowned for its ability to alter functional characteristics such as viscosity, rheology, texture, and sensory properties of the food product. The functional properties of β-glucans are directly linked to their origin/source, molecular weight, and stru...

The aim of this research was to investigate the effect of Pulsed Electric Fields (PEF) treatments (electric field strengths 2 and 4.4 kV/cm combined with specific energy inputs between 48 and 484 kJ/kg) on the thermal and pasting properties of oat flours. Colour, β-glucan content, particle size distribution, morphological characteristics, starch sh...

Thousands of bioactive peptides have been discovered from protein hydrolysates and the information is stored in databases. To discover bioactive peptides, the classic wet approach is mainly used. In silico approach, on the other hand, uses databases and informatics, and this eliminates trial and error, and saves time and cost associated with the cl...

The emerging beneficial characteristics of bio-active peptides have made them suitable candidates for a wide range of applications. While their usage as potent nutraceutical and pharmaceutical agents has been well-documented, applications of bio-active peptides in addressing sustainable agricultural challenges relating to biotic and abiotic stresse...

Flaxseed proteins and antioxidant peptides (AP) encrypted in their sequences were analysed in silico with a range of bioinformatics tools to study their physicochemical properties, allergenicity, and toxicity. Nine proteases (digestive, plant and microbial sources) were assessed for their ability to release known APs from 23 mature flaxseed storage...

β-galactosidase from Lactobacillus leichmannii 313 (LL313) was purified (4.5-fold, 11% purification yield), and characterised, giving optimal enzyme activity at pH 5.5 and 55 °C. Thermal inactivation of crude and purified enzyme showed first order inactivation kinetics. Deactivation energy (Ed) of 390.58 ± 34.94 kJ/mol (crude enzyme) and 404.17 ± 4...

The purpose of this study was to investigate the properties of starch in potatoes (Solanum tuberosum cv. Agria) after being treated with pulsed electric fields (PEF). Potatoes were treated at 50 and 150 kJ/kg specific energies with various electric field strengths of 0, 0.5, 0.7, 0.9 and 1.1 kV/cm. Distilled water was used as the processing medium....

Africa is known for its rich, ancient tradition in fermented foods. Among these, fermented dairy products represent one category that is widely consumed, contributing to the socio-economic development and food security of the people. In Africa, traditional food fermentation lends itself as a relatively cheap food processing technology that often im...

The application of proteomic and peptidomic technologies for food‐derived bioactive peptides is an emerging field in food sciences. These technologies include the use of separation tools coupled to a high‐resolution spectrometric and bioinformatic tools for prediction, identification, sequencing, and characterization of peptides. To a large extent,...