## Step 1: Define the symbolic representation of the variables
The variables are 'slices of pizza', 'apple pies', and 'fruit salads', which we can denote as $x_0$, $x_1$, and $x_2$ respectively.

## Step 2: Convert the objective function into a symbolic representation
The objective function to minimize is $4 \cdot (\text{slices of pizza})^2 + 6 \cdot (\text{slices of pizza}) \cdot (\text{apple pies}) + 5 \cdot (\text{fruit salads})^2 + 2 \cdot (\text{apple pies})$. In symbolic terms, this is $4x_0^2 + 6x_0x_1 + 5x_2^2 + 2x_1$.

## 3: Define the constraints in symbolic notation
1. The tastiness rating of slices of pizza is 18: $18x_0$.
2. Slices of pizza each contain 23 grams of carbohydrates: $23x_0$.
3. The tastiness rating of apple pies is 11: $11x_1$.
4. There are 13 grams of carbohydrates in apple pies: $13x_1$.
5. Fruit salads have a tastiness rating of 8 each: $8x_2$.
6. Fruit salads contain 21 grams of carbohydrates: $21x_2$.
7. The total combined tastiness rating from slices of pizza squared, and apple pies squared must be 79 or more: $(18x_0)^2 + (11x_1)^2 \geq 79$.
8. The total combined tastiness rating from apple pies, and fruit salads has to be 36 at a minimum: $11x_1 + 8x_2 \geq 36$.
9. The total combined tastiness rating from slices of pizza plus apple pies plus fruit salads has to be equal to or greater than 36: $18x_0 + 11x_1 + 8x_2 \geq 36$.
10. You need to get at least 30 grams of carbohydrates of from slices of pizza squared, and apple pies squared: $(23x_0)^2 + (13x_1)^2 \geq 30$.
11. You need to get at least 22 grams of carbohydrates of from apple pies plus fruit salads: $13x_1 + 21x_2 \geq 22$.
12. You must get at least 48 grams of carbohydrates of from slices of pizza, apple pies, and fruit salads: $23x_0 + 13x_1 + 21x_2 \geq 48$.
13. At least 48 grams of carbohydrates must come from slices of pizza, apple pies, and fruit salads: $23x_0 + 13x_1 + 21x_2 \geq 48$.
14. Six times the number of slices of pizza squared, plus -2 times the number of fruit salads squared must be at least zero: $6x_0^2 - 2x_2^2 \geq 0$.
15. Ten times the number of apple pies, plus minus four times the number of fruit salads has to be greater than or equal to zero: $10x_1 - 4x_2 \geq 0$.
16. The total combined tastiness rating from slices of pizza and apple pies must be as much or less than 190: $18x_0 + 11x_1 \leq 190$.
17. At most 117 grams of carbohydrates can come from slices of pizza plus apple pies: $23x_0 + 13x_1 \leq 117$.

## 4: Create a symbolic representation of the problem
```json
{
    'sym_variables': [
        ('x0', 'slices of pizza'), 
        ('x1', 'apple pies'), 
        ('x2', 'fruit salads')
    ], 
    'objective_function': '4*x0^2 + 6*x0*x1 + 5*x2^2 + 2*x1', 
    'constraints': [
        '18*x0 = 18', 
        '23*x0 <= 165', 
        '11*x1 = 11', 
        '13*x1 <= 165', 
        '8*x2 = 8', 
        '21*x2 <= 165', 
        '(18*x0)^2 + (11*x1)^2 >= 79', 
        '11*x1 + 8*x2 >= 36', 
        '18*x0 + 11*x1 + 8*x2 >= 36', 
        '(23*x0)^2 + (13*x1)^2 >= 30', 
        '13*x1 + 21*x2 >= 22', 
        '23*x0 + 13*x1 + 21*x2 >= 48', 
        '23*x0 + 13*x1 + 21*x2 >= 48', 
        '6*x0^2 - 2*x2^2 >= 0', 
        '10*x1 - 4*x2 >= 0', 
        '18*x0 + 11*x1 <= 190', 
        '23*x0 + 13*x1 <= 117'
    ]
}
```

## 5: Implement the optimization problem using Gurobi
```python
import gurobi

# Define the model
model = gurobi.Model()

# Define the variables
x0 = model.addVar(name="slices_of_pizza", lb=-gurobi.GRB.INFINITY, ub=gurobi.GRB.INFINITY)
x1 = model.addVar(name="apple_pies", lb=-gurobi.GRB.INFINITY, ub=gurobi.GRB.INFINITY)
x2 = model.addVar(name="fruit_salads", lb=-gurobi.GRB.INFINITY, ub=gurobi.GRB.INFINITY)

# Objective function
model.setObjective(4*x0**2 + 6*x0*x1 + 5*x2**2 + 2*x1, gurobi.GRB.MINIMIZE)

# Constraints
model.addConstr(18*x0 == 18, name="tastiness_pizza")
model.addConstr(23*x0 <= 165, name="carbohydrates_pizza")
model.addConstr(11*x1 == 11, name="tastiness_apple_pies")
model.addConstr(13*x1 <= 165, name="carbohydrates_apple_pies")
model.addConstr(8*x2 == 8, name="tastiness_fruit_salads")
model.addConstr(21*x2 <= 165, name="carbohydrates_fruit_salads")
model.addConstr((18*x0)**2 + (11*x1)**2 >= 79, name="tastiness_pizza_apple_pies")
model.addConstr(11*x1 + 8*x2 >= 36, name="tastiness_apple_pies_fruit_salads")
model.addConstr(18*x0 + 11*x1 + 8*x2 >= 36, name="tastiness_total")
model.addConstr((23*x0)**2 + (13*x1)**2 >= 30, name="carbohydrates_pizza_apple_pies")
model.addConstr(13*x1 + 21*x2 >= 22, name="carbohydrates_apple_pies_fruit_salads")
model.addConstr(23*x0 + 13*x1 + 21*x2 >= 48, name="carbohydrates_total")
model.addConstr(6*x0**2 - 2*x2**2 >= 0, name="slices_fruit_salads")
model.addConstr(10*x1 - 4*x2 >= 0, name="apple_pies_fruit_salads")
model.addConstr(18*x0 + 11*x1 <= 190, name="tastiness_pizza_apple_pies_limit")
model.addConstr(23*x0 + 13*x1 <= 117, name="carbohydrates_pizza_apple_pies_limit")

# Optimize the model
model.optimize()

# Print the solution
if model.status == gurobi.GRB.OPTIMAL:
    print("Objective: ", model.objVal)
    print("Slices of pizza: ", x0.varValue)
    print("Apple pies: ", x1.varValue)
    print("Fruit salads: ", x2.varValue)
else:
    print("The model is infeasible")
```