## 4 Discussion  
When we think about meat alternatives, typically plant proteins are considered because they are healthy, cheap, and are already a part of most diets [22]. Nowadays plant-based products regularly enter the market, aiming at replacing meats [34; 35]. These products are mainly based on soy, wheat, or pea protein or a mixture of them [36]. The most common meat alternatives are based on soy protein; however, pea protein-based products are gaining more and more popularity [20], because soy and wheat products cause food intolerances for a significant number of customers. Our experiments focused mainly on pea protein-based products. A consumer survey already revealed that freshness is the second most important food choice criterion, and only the price proved to be more important [37]. However, another important aspect is a long shelf-life. These consumer expectations make great demands on effective management and control of food spoilage. The food microbial spoilage could be caused by enzymatic or microbiological processes but the microbial spoilage affects primarily the product shelf life [38]. Only a few data are available about the food safety risk of plant-based meat analogues. [PERSON] et al. [39] tested the microbial spoilage of soy- and wheat-based canned meat analogues, and the usual heat treatment (121 \({}^{\circ}\)C/30 min) proved to be adequate for canned plant-based meat analogues. [PERSON] et al. [40] compared the microbial spoilage of chicken roll and meatless roll, but no differences were revealed. Due to their high protein and moisture content, and almost neutral pH, the plant-based meat analogues are susceptible to spoilage [41]. The aim of this work was the investigation of the microbiological quality of meals that are directly consumed. If microbial contamination is detected, this is usually caused by raw materials, therefore the evaluation of raw materials' microbial quality is of great importance. Our experiments were set up to observe the microbial spoilage caused only by the intrinsic effects of ready-made meals [42], namely by the ingredients. Therefore, the hot meal pairs were prepared identically, the only difference was in the meat/meat analogue ingredient. Typical food safety problem of households is the inappropriate storage of cooked food. Samples stored at room temperature and at 5 \(\pm\) 2 \({}^{\circ}\)C could be considered as a simulation of common household situations [43]. The pH values of the vegan meatball and vegan cabbage casserole were higher (0.5 more on the average) than their meat-containing counterparts. The pH values of spaghetti Bolognese were similar, probably due to the significant amount of tomato sauce. _Enterobacteriaceae_ could be present in food as part of natural microflora, but post-process contamination is the more significant factor regarding food quality. Members of _Enterobacteriaceae_ family are responsible for spoilage of variety of foods such as meats, dairies, fruits, and vegetables, etc. They can be found also in soil or water so their control is significant for food hygiene [44]. If _Enterobacteriaceae_ are present in heat-treated food, a post-process contamination is implicated. No _Enterobacteriaceae_ were detected in refrigerated samples. Two unrefrigerated samples contained _Enterobacteriaceae_, and both samples were \begin{table}
\begin{tabular}{c c} \hline \hline
**Food** & **pH** \\
**Mean \(\pm\) StDev * \\ \hline Spaghetti Bolognese & 5.3 \(\pm\) 0.2 \\ Vegan spaghetti Bolognese & 5.5 \(\pm\) 0.1 \\ Cabbage casserole & 5.9 \(\pm\) 0.1 \\ Vegan cabbage casserole & 6.4 \(\pm\) 0.1 \\ Meat ball & 6.2 \(\pm\) 0.1 \\ Vegan meat ball & 6.6 \(\pm\) 0.1 \\ \hline \hline \end{tabular}  
* Mean \(\pm\) standard deviation of seven measurements of the seven storage days are shown.  
\end{table} 
Table 3: The pH values of processed foods. the vegan meatball. It can be assumed that post-process contamination occurred, and ambient temperature is adequate for _Enterobacteriaceae_ proliferation [44].