3.1.1 Quantification and gravimetric composition of solid wastes generated

For 1 month, in the three community restaurants, the solid waste generated in all stages of the meal production process was weighed on a mechanical scale, model ruler, with a capacity of up to 150 kg and precision digital scale capacity of up to 5 kg (TGK-2261 model). A direct weighing technique was used (Figure 2). The mass balance was used in the prepreparation stage of the vegetables, whose peeling was done in the equipment "tuber peeler" [7]. The gravimetric composition of the generated residues was performed using Eq. (1).

$$\text{Gravitational composition} = \frac{\text{weight of solid waste by type}}{\text{total weight of solid waste generated}} \times 100 \quad \text{(1)}$$

For the analysis of organic solid waste, the total production of the preparations to be served at meals, the leftovers (prepared and undistributed preparations) and the food scraps (preparations distributed and not consumed by the diners) were weighed. From this analysis, the percentage of leftovers (Eq. (2)) and index of food scraps (Eq. (3)) were calculated.

Figure 2. Direct weighing of solid waste generated during the production of meals.

$$\text{Leftoverers} \%= \frac{\text{Leftover weight}}{\text{Weight of metal produced}} \times 100\tag{2}$$

$$\text{Index of food carsps} = \frac{\text{Weight of food carsps}}{\text{Distributed metal weight}} \times 100\tag{3}$$

## 4. Characterization of organic solid waste in meal production

The amount of waste generated during the study period varied according to the number of meals produced in the three community restaurants, as can be seen in Table 1.

Among the solid residues, organics were generated in greater quantities, followed by recyclable residues (Table 1). Similar results were obtained by Zotesso et al. [23] and Colares and Figueiredo [8], who found that 82% and 88% of the residues produced were of organic origin, respectively.

Table 2 shows the gravimetric composition of the solid waste generated in the three restaurants. It was observed that of recyclable waste, there was more plastic, followed by cardboard. The carton came from boxes of primary, secondary, and tertiary packaging of meats, ice creams, tea, processed dessert, sugar, eggs, cups, and disposable napkins, among other materials.

The amount and type of waste generated in community restaurants were related to the planned menu and specificity of meal production.

Failure to plan the menu, caused by repeating meals in a short time and replicating cooking techniques on the same menu, can lead to nonacceptance by consumers, and consequently, food waste by the increase in leftovers and remains. Table 3 presents the average amount of meals produced in the three community restaurants and the generation of residues from leftovers and food scraps.

At the menu planning stage, it is essential to use preventive measures that reduce the generation of solid waste. For example, using food directly from the harvest and diversifying preparation techniques can positively influence the formation of healthier eating habits by consumers, as well as a more sustainable menu through the reduction in food waste and solid waste [25, 26].

There was a failure at the menu planning stage in the community restaurants evaluated in this study. This occurred due to the presence of the same type of vegetable (potato) in two meals of the same menu (in the entree and in the garnish), which led to an excess in food remains that day (R1). Similarly, an excess of


#### Table 1.

Solid waste generated and the number of meals produced per month in the three community restaurants.


### Management of Organic Solid Waste in Meal Production DOI: http://dx.doi.org/10.5772/intechopen.83535

## Table 2.

Gravimetric composition of the solid waste generated in the three community restaurants over the period of 1 month.


#### Table 3.

Weight of meals produced daily, meals consumed, leftovers, and food scraps.

sauce (mixed meat and meatballs of chicken) was observed in certain meals, resulting in a high quantity of leftovers and food scraps.

Regarding the frying oil, a high level of consumption was observed since the frequency of frying was quite high in the three community restaurants. Although contributing from 1.1 to 1.7% of organic solid waste (Table 2), during the data collection period, it was observed that this oil was used for many days before being changed, which constitutes an improper practice. It was also observed that on the day of the oil change, a large amount of metal residue was found in the fryer since the oil was conditioned in this vessel. In spite of this, the used oil was sent to a recycling company for biodiesel production.

A solution for reducing the production of these residues would be to diversify the preparation technique, for example, through the introduction of roasting techniques, which would reduce the need to fry the food [7].

In this present research, the factors that contribute to food waste were observed throughout the production process, and consequent generation of solid waste in the corresponding stages is shown in Table 4.
