Strawberries (Fragaria x ananassa) are cultivated extensively in Brazil using cultivars that overcome edaphoclimatic challenges and enhance production potential [1] . Among the factors that influence plant growth, photoperiod plays a crucial role in their metabolism and phenological development. The vegetative stage benefits from increased temperature and day length, while shorter days and lower temperatures lead to floral induction. The day-neutral cultivars San Andreas and Aromas, are used for cultivation in the southern region of Brazil, as they have requirements compatible with the climatic conditions and good physical and chemical quality for commercial purposes, and also the “San Andreas” cultivar is known for its high productivity and resistance to diseases such as gray mold (Botrytis cinerea) and anthracnose (Colletotrichum acutatum), which are essential traits for ensuring high yields and reducing the need for pesticides [2] - [4] . The variety was also donated by a producer from Ponta Grossa, who already uses it successfully, ensuring reliability in its selection and validation for the region.

Strawberry production in Brazil is still limited, especially in the foreign market [5] . This is due to the fruit’s sensitivity to mechanical and pathological damage, which can compromise visual quality during commercialization [6] . Given that it is a non-climacteric fruit, strawberries show few metabolic changes following harvest, with a reduction in respiration rate and senescence [7] .

The use of chemical control is frequently employed in strawberry production due to the high susceptibility of the fruit to pathogens during the various stages of ripeness. Pathogens of the genera Botrytis and Rhizopus are especially damaging when the fruit is approaching physiological ripeness and can cause significant losses in fruit production and storage [8] . Chemical, thermal, or sanitizing treatments can be applied to reduce the development of pathogens. Peracetic acid (an organic oxide with rapid biocidal action and no residue) and calcium (which strengthens the cell wall by forming pectates that are resistant to fungal enzymes) are examples of such treatments [9] .

Physical control methods, such as forced cooling and hydrocooling, reduce respiration and fruit senescence, thereby extending the post-harvest life of the fruit [10] . It is common practice in Brazil to refrigerate strawberries at 0˚C with high humidity (95%) to preserve them for up to seven days. This method of refrigeration prevents degradation and maintains organoleptic quality [6] . Hydrocooling, which entails immersing or spraying the fruit with ice water, provides rapid and uniform cooling without causing physical damage [11] . The method can reduce microbial activity without compromising the integrity of the fruit when applied at a temperature of 2˚C [12] .

The two treatments complement each other synergistically, while hydro-cooling slows down physiological deterioration, peracetic acid prevents the proliferation of microorganisms. This combined strategy can result in an extended shelf life for strawberries compared to conventional methods, without compromising food safety or the sensory quality of the fruit. Additionally, it addresses the growing demand for more sustainable post-harvest methods by reducing the use of synthetic fungicides and minimizing chemical residues [13] . Furthermore, studies on other vegetables, such as lettuce and green onions, indicate that hydro-cooling is effective in reducing mass loss and maintaining visual quality. Hydro-cooling at 4˚C for 5 minutes, followed by storage at 5˚C, helps maintain the water balance in the leaves, delaying wilting and extending the product’s shelf life [14] [15] . Although these studies do not directly involve strawberries, the results suggest that hydro-cooling may be a promising technique for prolonging the shelf life of various horticultural products.

The use of resistant packaging (such as polyethylene plastic tubs with PVC film) is essential to reduce mechanical damage and make commercialization easier. However, this packaging can lead to the development of a microclimate that favors the proliferation of pathogens [16] . The objective of this study was to evaluate the efficacy of pre-and post-harvest sanitization methods on the preservation of “San Andreas” strawberries. The data in this study was previously used in a master’s thesis [17] which evaluated the effectiveness of pre-and-post-harvest sanitization and post-harvest hydrocooling, and extend the shelf life of “San Andreas” strawberries.

Strawberries of the San Andreas cultivar produced in the city of Ponta Grossa, Paraná, in a protected cultivation system with fertigation in slabs without prior phytosanitary management were used. In addition to the control, five different treatments were analyzed: pre-harvest application of peracetic acid; a combination of pre-harvest peracetic acid and post-harvest hydrocooling; post-harvest hydrocooling only; hydrocooling followed by post-harvest application of CaCl₂; and a combination of post-harvest hydrocooling and peracetic acid.

The greenhouse area was divided into two sections, with only one receiving a single dose of PRO15® on the strawberry plants. The PRO15® was dissolved in a ratio of 15 ml per 10 L of water, following the instructions provided by the manufacturer. The compound has a sanitizing action through peracetic acid and is recommended for use on strawberry crops, with no deficiency or residual action.

The fruits were harvested when at least two-thirds of their epidermis exhibited pigmentation. They were later transported to the Laboratory of Biotechnology Applied to Fruit Farming at the State University of Ponta Grossa (UEPG). The strawberries were then divided into those that had or had not received a pre-harvest application of peracetic acid for subsequent post-harvest treatment. A total of 10 L of distilled water were used, with 1/4 of the solution in liquid form and 3/4 frozen, until the solution temperature was adjusted to 1˚C. The hydro-cooling process consisted of immersing 20 kg of fruit into the solution, maintaining a 1:2 water-to-fruit ratio. The fruits being monitored and kept in the solution until they achieved 7/8 of the total cooling [18] . This was observed after one hour of immersion, when the pulp temperature reached 2.5˚C. The treatment involving the addition of calcium chloride (CaCl₂) utilized the hydro-cooled medium with 2% soluble CaCl₂. For the post-harvest peracetic acid treatment, 15 ml of the product was added to the hydrocooled medium. The fruits were randomly selected and packed in PET containers with ventilation holes to facilitate airflow and maintain humidity. The packages had a mass of approximately 80 g and were stored at room temperature (20˚C ± 2˚C) and in a cold room (0˚C ± 2˚C) without relative humidity control.

The physicochemical analyses were carried out one day after harvest. The fruits at room temperature were evaluated after 2 and 4 days while the fruits in cold storage were evaluated after 7 and 9 days in cold storage, plus 2 days at room temperature, simulating commercial settings. The five most homogeneous strawberries in each package were subjected to analysis to determine the loss of mass, firmness, total soluble solids (SS), titratable acidity, converted into % citric acid, anthocyanin content, analyzed by the method described by Lee and Francis and total polyphenols, analyzed according to the method described by Singleton and Rossi which uses the Folin-Ciocalteau reagent, both adapted by Nunes, Brecht, Morais and Sargent [19] .

The experiment was conducted in a completely randomized design (CRD), considering the homogeneity of the units, with four replications for each treatment. Statistical analyses were carried out using the software SISVAR 5.6, the data was organized for an initial evaluation and then subjected to regression analysis and the F-test (p < 0.05), analysis of variance (ANOVA) with the comparison of means using the Tukey test (p < 0.05) and SNK (p < 0.05) for non-normal data.