## 1 Introduction  
_Streptococcus mutans_ is a Gram-positive bacterial involved in oral health issues, as it is responsible for tooth decay, which triggers other illnesses such as gingivitis and periodontitis [1]. Some of the most commonly used chemical agents to control plaque and tooth decay related to _S. mutans_ are chlorhexiidine and tridosan; however, long-term use of these substances causes secondary effects such as brown staining in teeth, altered taste, and scaly lesions in the alveolar mucosa [2]. Currently, the use of natural antimicrobial agents with efficient performance in the inhibition of pathogenic microorganisms has become an interesting alternative, due to the secondary effects caused by antibiotics, and the development of bacterial resistance [3]. In this regard, around 30,000 plant species are found in Mexico; from these, 33% are considered to have medicinal properties, and only 5% have been accounted for, with chemical, pharmaceutical, and biomedical validation [4; 5]. Among them, we can find several plants that grow in the wild, in arid and semi-arid regions of Mexico. The acidic cactus pear, or xoconostle 'Ulapa', is an acid fruit of the cactus known as nopal, and it has anti-inflammatory, antioxidant, and antimicrobial properties [6; 7]. The health benefits associated with this fruit are related to its contents of fiber, phenols, flavonoids, betanins, vulgaxanthins, and ascorbic acid [8]. [PERSON] et al. [7] found a higher content of ascorbic acid in the pulp, while seeds presented a higher content of phenols and flavonoids. On the other hand, [PERSON] et al. [8] detected a high total phenolic content (278 mg GAE/100 g) and antioxidant activity (9.80 mmol TE/100 g) in xoconostle 'Ulapa' pulp. [PERSON] and [PERSON] [6] reported that aqueous extracts of xoconostle present an inhibitory effect when used at a concentration of 10% (\(v/v\)) against _E. coli_ O157: H7. However, the main use of xoconostle lies in Mexican cuisine as a condiment, with the development of traditional candies, sauces, and jams being an underutilized resource [7; 8]. On the other hand, _Jatropha dioica_ is a plant known as dragon's blood, and it has been employed in Mexican traditional medicine as a stem infusion or rhizome mastication to prevent tooth mobility, and as an analgesic for pain relief [9]. Some species of _Jatropha_ have been demonstrated, in methanolic extracts of the rhizomes, to trigger anti-inflammatory activity in rats with a dose of 200 mg/kg body weight [10]. Furthermore, the hydroalcoholic extracts of dragon's blood rhizomes present antioxidant and antimicrobial activities at a concentration of 50 mg/mL against fungi, and against Gram-positive and Gram-negative bacteria [11; 12]. The antioxidant and antimicrobial properties of _Jatropha dioica_ are related mainly to its content of phenolic compounds [13]. One of the problems that arises when using natural extracts of plants as an antimicrobial substance is contamination by fungi and molds, probably during the extraction of fresh materials, since aseptic techniques are not followed during the extraction processes [14]. Autoclave sterilization can solve this problem in plant extracts [14]. However, autoclave sterilization uses high process temperatures, which may cause some modifications in the bioactive compounds of the plant extracts. In this context, many functional ingredients, such as polyphenols and flavonoids, are thermally sensitive, and the amounts of these active components that remain during the process of thermal sterilization at high temperatures are important for the maintenance of their antioxidant, antimicrobial, and other properties, which are linked to health benefits [15]. Extracts of xoconostle and dragon's blood can be a viable alternative against _Streptococcus mutans_, due to its antimicrobial and antioxidant properties; however, it is still unknown as to whether autoclave-sterilization affects the functional properties of these extracts.