(Food Science and Technology Research, 2019, Volume 25, Issue 4, Pages 597-605, Released on J-STAGE September 26, 2019)
Recently, eating insects has become not only an alternative source of proteins that offers a cheap and sufficient nutrient intake in the human diet in developing countries but also very popular in developed countries that concerns about healthy food. Edible insects are the new trend on the food market worldwide because they are not only a healthy food source and that is highly nutritious that is rich in protein, healthy fats, vitamins, fibre and minerals with low carbohydrates but also are more environmentally friendly to raise than other livestock protein sources.
In Thailand, eating insects is not new. Thai people have had a long history and tradition of using over 200 different insect species as food. Crickets are the most common species farmed. Recently over 20 000 cricket farms have been established in Thailand. However, only two species of edible crickets, field crickets (Gryllus bimaculatus (Orthoptera: Gryllidae)) and house crickets (Acheta domesticus (Orthoptera: Gryllidae)), are farmed economically.
This present work has been performed to determine the amino acid profile, fatty acid profile, nutritional composition, and mineral content of A. domesticus and G. bimaculatus. In addition, protein solubility and functional properties were also investigated. This information would help to perceive the plausible of using insects as health food and to record information of the nutritional contents of these two commercial insect species.
Results & Discussion
The results indicated that protein was the major component of the nutrient composition of the crickets. The requirement to be called high protein food according to WHO/FAO, is a 10 g/100 g edible part. Therefore, these crickets can be an attractive alternative protein source. The results also showed that these crickets contained low fat contents compared with other edible insects. High fat content considered to hinder the process ability and the food products shelf life, therefor, the low fat content makes these crickets interesting for food industries. However, the overall nutrient composition of these two species of crickets surpassed that of conventional livestock with the same weight.
| A. domesticus | G. bimaculatus | |
|---|---|---|
| Components | % dry matter | |
| Moisture | 6.3 ± 0.04 | 3.0 ± 0.03*** |
| Protein | 71.7 ± 0.5 | 60.7 ± 0.4*** |
| Lipid | 10.4 ± 0.1 | 23.4 ± 0.1*** |
| Ash | 5.4 ± 0.3 | 2.8 ± 0.06*** |
| Fibre | 4.6 ± 0.2 | 10.0 ± 0.3*** |
| Carbohydrate | 1.6 ± 0.1 | 0.1 ± 0.01*** |
| Mineral content | mg/100g dry matter | |
| Calcium (Ca) | 149.75 ± 7.16 | 105.14 ± 9.31** |
| Sodium (Na) | 101.44 ± 7.80 | 88.84 ± 20.43 |
| Potassium (K) | 389.92 ± 1.38 | 321.71 ± 6.21** |
| Phosphorus (P) | 899.33 ± 36.19 | 702.02 ± 6.35** |
| Magnesium (Mg) | 136.58 ± 4.92 | 72.94 ± 2.64*** |
| Iron (Fe) | 8.83 ± 3.88 | 7.16 ± 1.28 |
| Copper (Cu) | 4.86 ± 0.35 | 3.86 ± 0.18* |
| Manganese (Mn) | 4.40 ± 0.08 | 3.40 ± 0.13*** |
| Zinc (Zn) | 19.61 ± 0.83 | 14.39 ± 2.29* |
Table 1. Proximate nutrient composition and mineral content of the two cricket species.
Some main minerals (Na, Mg, P, K, and Ca) and trace minerals (Mn, Fe, Cu, Zn) contents in both cricket species were different (Table 1). The results showed that phosphorus was the highest, followed in order by potassium, calcium and sodium. Phosphorus is essential for ATP and nucleic acid synthesis (RNA and DNA) and protein production, which is particularly phosphorus rich. Calcium, phosphorus, and magnesium are important constituents of bone. The calcium concentration of the crickets in this study was higher than that in milk (90–130 mg/100 g), suggesting that crickets could be used as an alternative source of calcium. The data obtained from this study were consistent with data from other edible insect species that they contained more iron, zinc and calcium, which are essential for human health, than conventional food such as beef, pork, and chicken. The mineral composition showed that crickets have the potential to provide good sources of dietary minerals.
Amino acid composition from these edible insects as related to the human diet has to be assessed through the amino acid content. All essential amino acids (EAAs) were present in both A. domesticus (42.7%) and G. bimaculatus (40.4%). This result indicated that the EAA contents of both crickets were comparable to those of egg, chicken, pork and beef (dry matter), which are considered the main protein sources of the human diet.
[The above is a partial extract of an original article. For the full article, please visit here.]
