Scientific Studies of Mealworms

**Abstract**

Mealworms (Tenebrio molitor) could be a great food source for people because they are nutritious and have a low impact on the environment. To grow mealworms well, it’s important to feed them the right diet. This study looked at how adding fresh plant materials like carrot, orange, and red cabbage to their diet affects mealworm growth and nutrition. For four weeks, mealworm larvae were fed either plain wheat bran or wheat bran mixed with carrot, orange, or red cabbage. We checked how well the larvae and pupae survived, how quickly they grew, and their nutritional content and antioxidant levels. The extra plant materials did not greatly change survival rates or nutritional content, but mealworms grew 40%–46% heavier with the supplemented diets. This suggests that adding these plants can make mealworm farming more efficient.

**Keywords:** mealworm, feed supplements, growth, nutrients, antioxidants

**1. Introduction**

Eating insects is common in some parts of the world, like Africa and Asia, but not so much in Western countries. Recently, there’s been more interest in eating insects as a sustainable food choice. Insects are high in protein, good fats, and other nutrients. They also need less land and water than traditional animals. More than 1500 edible insect species are known, but care is needed when farming non-native insects because they can become pests. For example, palm weevils are eaten in many places but can also harm palm trees in California.

Mealworms, also known as Tenebrio molitor, have been farmed in the US for over 70 years. They are a good option for farming because they are high in protein, efficient at converting feed into growth, and have a low environmental impact. While mealworms can be raised on just wheat bran, adding other foods like potatoes, carrots, and cabbage can provide extra nutrients. This study explores if adding antioxidants from carrots, oranges, and red cabbage can improve mealworm growth and health.

**2. Materials and Methods**

**2.1. Materials**  
Mealworm larvae and wheat bran were bought from Mulberry Farms. Carrots, oranges, and red cabbages were bought from a grocery store and kept in the fridge. Chemicals for testing were purchased from Fisher Scientific.

**2.2. Feeding**  
Mealworm larvae were divided into four groups: (1) 50 grams of wheat bran only, (2) 50 grams of wheat bran with 20 grams of carrot, (3) 50 grams of wheat bran with 20 grams of orange, and (4) 50 grams of wheat bran with 20 grams of red cabbage per day. Each group had 60 grams of mealworms. They were fed for four weeks, and the food was replaced weekly.

**2.3. Growth Performance**  
Each day, we removed and counted dead larvae and pupae. We also checked how long it took for pupae to turn into beetles and measured the average weight of the larvae each week. 

**2.4. Sample Preparation**  
Every week, we took samples of mealworms, fasted them for 24 hours, then froze them to kill them. We ground the mealworms for analysis and used special tools to prepare samples for testing.

**2.5. Proximate Analysis**  
We measured the moisture, fat, protein, ash, and carbohydrate content of mealworm larvae according to standard methods.

**2.6. Ferric Reducing Power**  
We tested the mealworms' ability to reduce ferric ions, which is a measure of antioxidant activity.

**2.7. Ferrous Chelating Activity**  
We tested the mealworms' ability to bind with ferrous ions to see how well they chelated metals.

**2.8. ABTS Radical Scavenging Activity**  
We measured how well the mealworms could neutralize free radicals using a specific chemical test.

**2.9. Statistical Analysis**  
We repeated the tests multiple times and used statistical tools to analyze the results.

**3. Results and Discussion**

**3.1. Growth Performance**  
Over four weeks, the survival rates and development times of mealworms were similar across all diets. However, mealworms fed with carrot, orange, and red cabbage grew significantly faster and were heavier by 40%–46% compared to those fed only wheat bran. This means that adding these plant materials can make mealworm production more efficient.

**3.2. Proximate Composition**  
The basic nutrient content of mealworms did not change much with the added plant materials. This is because the plants did not provide enough major nutrients to affect the mealworms' overall composition.

**3.3. Antioxidant Activity**  
While insects have their own ways to handle oxidative stress, adding antioxidants from carrots, oranges, and red cabbage did not greatly increase the mealworms' antioxidant levels. This may be due to the low concentrations of antioxidants in the plants or because mealworms already manage oxidative stress effectively.

**4. Conclusions**

Adding fresh carrot, orange, and red cabbage to the mealworm diet improved their growth rate without affecting survival or overall nutrient content. No significant increase in antioxidant levels was observed. This suggests that plant supplements can help mealworms grow faster, which can make mealworm farming more efficient.