Study of safety indicators of salted Bracken Fern Pteridium Aquilinum (L.) Kuhn harvested in the Krasnoyarsk Krai

. The article first defined the hygienic safety indicators of salted Bracken Fern Pteridium Aquilinum (L.) Kuhn harvested in the Krasnoyarsk region and carried out a comparative analysis with the regulated safety indicators of salted vegetables and mushrooms established in the territory of the EAEU Customs Union. The harvesting and processing of Bracken Fern was assessed.


Introduction
Safe and quality food is a key requirement of today's market, both for the consumer and the producer. The consumer has begun to pay close attention to the quality and safety of food products, and the manufacturer must be clearly aware of its responsibility and maintain its reputation. The spirit of the new trends for a proper and healthy diet requires special vigilance with regard to the production of food, and scientists have the task of studying and researching the physical and chemical quality and safety indicators of raw materials used for the production of healthy products.
Literature provides a significant amount of information on the use of various plant raw materials, including the use of wild herbs, plants and berries, as a source of biologically active substances (BAS) [1][2][3][4][5]. Krasnoyarsk Krai is rich in food forest resources, has the potential to harvest wild-growing crops and provide the domestic and foreign consumer market with products of their processing. One of the poorly studied and promising for industrial processing is Bracken Fern which grows in the Krasnoyarsk Krai.
Common Bracken Fern (Pteridium aquilinum L. Kuhn.) -a perennial plant belonging to the spore genus of the vascular division, reaching a height of 150 cm, distributed virtually throughout Russia, up to the polar northern latitudes. Habitat includes deciduous and coniferous forests, shrub thickets, upland open terrain, and forest edge in pine, light and poor ground cover. Bracken Fern is a food plant until the beginning of leaf formation (vaia), when the height of the shoot from the soil is no more than 50-60 cm [6]. Thus, domestic and foreign authors investigate various indicators that determine, in their opinion, the safety of the fern. F we refer to the regulatory sources that regulate the safety indicators of the TR TS 021/2011 "On the safety of food products", fern as a type of plant raw materials is absent in this document. Section 1.4 "fruit and vegetable products" presents safety indicators for vegetables, mushrooms and their products. To determine the safety indicators it is necessary to assign the fern to a particular commodity group of vegetables or mushrooms.
On this issue in the literature and regulatory sources present different points of view. For example, in the textbook "Examination of wild fruits, berries and herbaceous plants. Quality and Safety" [5] gave a classification of herbaceous plants, presented in Figure 1. The authors identified the fern in the group of vegetable plants according to the classification features. In accordance with the requirements of the normative document GOST ISO 3493-2017 Interstate Standard "Spices. Vanilla" in Note 1, ferns and mushrooms are referred to "spore plants", which gives grounds to attribute the fern to the group of fungi. Thus, the analysis of literary and regulatory sources does not allow us to uniquely identify which product group refers to a fern and, accordingly, to establish a list of regulated indicators of safety for fresh and processed Bracken Fern. Currently, Bracken Fern in the food industry, in public catering and for sale to the consumer through the trade is used in salted form. In this regard, we analyzed the safety indicators of salted vegetables and mushrooms in the current interstate regulations of the TR TS 021/2011 "On the safety of food products" (Table 2). According to Table 2, the list of regulated safety indicators is different. For salted mushrooms by microbiological indicators of safety it is necessary to determine mesophilic sulfate-reducing clostridia and by hygienic indicators allowable levels of toxic elements are higher in comparison with vegetables, while the regulatory values of lead and pesticides are the same.
Thus, fern Pteridium aquilinum L. Kuhn is characterized by high nutritional value due to the content of BAS, organoleptic indicators, which determines its demand in the domestic and foreign consumer markets. However, fern can contain in its chemical composition poisonous glycosides and toxic elements that determine the danger to the human body. In this regard, the assessment of the processing potential of Bracken Fern in the Krasnoyarsk Krai and the study of safety indicators of its product processing has practical relevance and is an important topic for research

Discussion of results
In the Krasnoyarsk Krai OOO "Procurement and Production Complex of the Consumers Union" carries out economic activities on the harvesting and processing of Bracken Fern, the dynamics of harvesting is shown in Figure 2. Bracken Fern is collected in 6 districts, including the northeastern direction of Krasnoyarsk -Dzerzhinskoye; the southeastern Sayan Mountains -Dubenskoye, Shushenskoye, Ermakovskoye; the highlands of the eastern Sayan -Kuragino and the lowlands of the eastern Sayan -Kozulka. From 2012 to 2020, the average harvest and processing volume is about 687 tons of fresh fern per season -May, June, and July.

Fig. 2. Dynamics of fern harvesting of Krasnoyarsk Krai Krai Consumers Union
Salted Bracken Fern harvested by Krasnoyarsk Krai Consumer Union is successfully sold on the Russian market, but more is exported to the Asian market, which accounts for about 70% of the total processed volume. According to Figure 1, from 2012 to 2018, harvest volumes range from 400 to 800 tons per season, with 2019 characterized by the highest yields and processing capacity. In 2020, harvest decreased by 54% compared to 2019 due to restrictive measures during the COVID-2019 pandemic, which negatively impacted processing volumes and sales of salted ferns in the foreign market.
Currently, in the Krasnoyarsk Krai, only salted fern is obtained from fresh ferns. In this regard, we investigated the potential hygienic indicators of salted fern in 6 districts of Krasnoyarsk Krai and carried out a comparative analysis with the safety indicators of salted vegetables and mushrooms (Table 3). A comparative analysis of the potential safety indicators of the Bracken Fern, with the regulated indicators of salted vegetables and mushrooms, indicates that the standard values of the indicators of the studied samples do not exceed the permissible level.
Thus, the results of the analysis of the volumes of harvesting and processing of Common fern in the Krasnoyarsk Krai suggest the conclusion about the significant resource potential in the region and the limited method of processing -salting, which restrains the possibility of new food products on its basis. The results of the study of hygienic indicators of salted fern and their comparison with the regulated indicators of salted vegetables and mushrooms give grounds to assert that the product of fern processing meets the established safety requirements and can be used without restrictions for food purposes.