C. Draza, KB Yisa Njowe, MM Emmambuxsup>*
Dept. of Consumer and Food Sciences, University of Pretoria, Pretoria, Republic of South Africa
Introduction: Edible grey cricket protein was investigated
as a sustainable alternative to conventional animal-based proteins to
address global food security challenges and overcome consumer acceptance
barriers. This study characterised the physicochemical and functional
properties of myofibrillar, stromal protein fractions and whole protein
isolate extracted from grey crickets (Acheta domesticus) and
compared them with commercial protein ingredients. Freeze-dried adult
crickets (12 – 13 weeks old) were crushed and defatted using food-grade
hexane. A portion of defatted cricket flour was sequentially homogenised in
0.5 N NaCl and NaOH (pH 10). The saline extract was diluted five times with
distilled water to precipitate myofibrillar proteins. Cricket protein
isolates were alkaline-extracted at pH 10, and the supernatant was
neutralised. All extracts were freeze-dried to obtain protein fraction
powders and analysed.
The myofibrillar fraction demonstrated the highest water and oil absorption
capacities (3.87 g/g and 4.47 g/g, respectively), whilst the stromal
fraction exhibited the least (1.32 g/g and 3.07 g/g, respectively). The
cricket isolate exhibited competitive foaming and emulsifying capacities
(88.00% and 61.88%), comparable to commercial whey protein concentrate
(90.7% and 59.5%). The water solubility indices suggested that the insect
protein fractions are less soluble in water (21.3 – 61.1%) than whey protein
concentrate and isolates (84 – 87.7%). Myofibrillar proteins were
predominantly composed of β-sheet structures (58.0%). In contrast, stromal
fractions had a balance of β-sheet (45.1%) and α-helix content (40.3%),
while the total cricket isolates consisted of β-sheet (39.5%) and random
coil (33.1%) structures. The myofibrillar fraction demonstrated superior
gelation and surface hydrophobicity compared to the stromal fraction.
The findings offer valuable insights for developing innovative food products
that can utilise cricket proteins as sustainable alternatives to
conventional protein sources, thereby supporting circular food systems and
addressing global protein demands
Functional hydrocolloids for plant-based dairy and meat alternatives
Innovating with alternative proteins in new product development