# Physicochemical and Structural Properties of Freeze-Dried Lacto-Fermented Peach Snacks
## 1 Introduction  
The peach (_Prunus persica_) belongs to the genus _Rosaceae_. It is a drupe, inviting with its sweet taste and juicy flesh [1]. The country of origin of this fruit is China, where it is a symbol of longevity and prosperity due to its shape and sweetness. Considering economic and nutritional aspects, peaches are the second most important leafy fruit crop in the world [2]. The European Union is the second largest producer of this fruit after China. In 2017, the European Union's production of peaches and related fruits totaled 3.9 million tons, of which 760,000 tons were for processed products, which in the case of peaches are very popular and include canned peach products, pureed peaches, and peach juice [3]. Inaddition to their taste, peach fruits are valued for their nutritional properties. They are a rich source of essential nutrients, such as vitamin C, flavonoids, carotenoids, anthocyanins, and retinol [4]. Moreover, peach phenolic compounds, such as quercetin, catechins, and cyanidin derivatives, have antioxidant, antimicrobial, and anti-inflammatory effects [5]. The food market is very diverse, especially for the snacks segment, which continues to gain popularity among consumers [6]. The global snacking industry is steadily growing, and for many consumers, snacks have become a vital part of the daily diet [7]. Unfortunately, many commercially available snacks are low in nutritional value and contribute to health issues such as obesity and hypertension [8]. The current trend in the snack market is for manufacturers to emphasize their reduced fat and salt content in the formulation and increase protein, fiber, starch, and phytochemicals [9]. The market's demand for foods with greater nutritional value poses a challenge for food producers, especially when producing dried fruits with desirable sensory qualities. Consumer expectations for snacks are evolving; they now seek not only good taste but also health benefits and convenience. Snacks made with organic and natural ingredients are becoming increasingly desirable. Additionally, visual appeal, particularly color, plays a key role in consumer acceptance [10; 11]. The introduction of dried probiotic products has sparked rapid growth in this market niche [12]. Fermentation is a common food processing technology that allows food preservation. It not only extends shelf life but also enhances microbial safety by reducing the pH and inhibiting the growth of spoilage organisms. Lactic acid bacteria are commonly used in this context due to their effectiveness and functional properties [13]. As the demand for healthier food options increases and fresh fruits encounter challenges related to perishability and seasonality, the transformation of fresh produce into stable, value-added products has emerged as a notable trend. Within this landscape, dried fruits have gained considerable popularity. Various drying methods effectively lower water content to safe levels, with freeze-drying recognized as one of the most efficient and widely adopted techniques [14]. In addition to increasing stability and extending expiration, dried products are more economical due to their reduced weight and volume, thus reducing packaging, transportation, and storage costs [15]. The significance of this study can be attributed to its contribution to the development of innovative functional snacks that satisfy contemporary consumer demands for both health and taste. This research explores an innovative approach to creating shelf-stable, nutritious peach-based snacks enriched with probiotic benefits. The approach combines lactic acid fermentation with freeze-drying. In contradistinction to preceding studies, which predominantly concentrated on either fermentation or drying techniques in isolation, this study employed a distinctive approach by integrating both processes, thereby optimizing sensory and nutritional properties in a simultaneous manner.