Effect of Pretreatment with Low-Frequency Ultrasound on Quality Parameters in Gulupa (_Passiflora edulis_ Sims) [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON]  
1 Grupo de Investigacion en Optimac y Biotecnologia (QUIBO), Universidad Santiago de Cali, Calle 5 # 62-00, Cali 760035, Colombia; [EMAIL_ADDRESS] (V.C.M. ); [EMAIL_ADDRESS] (E.F.-L.)
2 Grupo de Investigacion Biotecnologia, Facultad de Ingenieria, Universidad de San Buenauventura Cali, Carrera 122 # 6-65, Cali 760032, Colombia 2  
[PERSON]  
3 Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, [PERSON] 1, 64100 Teramo, Italy; [EMAIL_ADDRESS]
4 Grupo de Investigacion en Process Agroximetarios y Biotecnologicos (GIPAB), Escuela de Ingenieria de Alimentos, Universidad del Valle, Cali 760032, Colombia; [PERSON] and Nutrition Department, Faculty of Health Science, Pontificia Universidad Javeriana Cali, C1 18 No 118-250, A.A. 26239, C.P., 760031, Colombia 5  
Research Group Biotecnico, Faculty of Basic Sciences, Technology and Engineering, Universidad Nacional Abireta y a Distancia, Palarina Jorica 3, 53531, Colombia; [EMAIL_ADDRESS]  
M.P. ; [PERSON] [PERSON]; [PERSON] Effect of Pretreatment with Low-Frequency Ultrasound on Quality Parameters in Gulupa (_Passiflora edulis_ Sims) Pulp. _Appl. Sci._ **(**_Passiflora edulis_ Sims) Pulp. ** **(**_Passiflora edulis_ Sims) Pulp. is produced mainly in Brazil, followed by Venezuela, Colombia, and the rest of the tropical countries [1], from where it is mainly exported to the European Union. Colombia has the most remarkable diversity of the genus _Passiflora_, among which _P. edulis_ f. _flaviarap_ (yellow passion fruit), _P. edulis_ f. _edulis_ (purple passion fruit or gulupa), _P. ligularis_ (sweet granadilla or grenadia), and _P. molissima_ (banana passion fruit or curuba) are the most desired in international markets. In 2019, Colombia exported 8725 tons of Gulupa, representing 2.9% of the world market [2]. The _gulupa_ fruit selected for export is harvested in an intermediate ripening stage (3 or 4) on the scale proposed by [PERSON] et al. [3]. Maximum pulp yields are reached in this state, representing between 35 and 50% of the total weight. _Gulupa_ is an excellent source of ascorbic acid, thiamine, riboflavin, niacin, calcium, and phosphorus. Its pulp is used to prepare juices and soft drinks. It has essential nutrients with antioxidant properties, such as vitamins, polyphenolic compounds, carotenoids, anthocyanins (cyanidin-3-O-\(\beta\)-D-glucopyranoside), and amino acids that make it attractive for consumption [4; 5]. As it is a climacter fruit, during the postharvest, transport, storage, and marketing period, it continues its normal ripening process, which can cause it to reach maturity before reaching the final consumer, losing its organoleptic quality and causing economic losses for exporting companies of up to 15% of the total volume shipped [5]. Therefore, the transformation of _gulupa_ into the pulp as a minimally processed product represents for producers the opportunity to add value to their product and at the same time reduce exportation over costs by transporting less than half the volume, a process that would allow them to control adequately the quality of the product, preserving its nutritional characteristics and obeying changes in consumer preferences. Emerging technologies for food preservation and transformation seem to be the best alternative to achieve the mentioned characteristics. This evolution forces food industries to adapt to new production techniques and current market demands, integrating social and natural sciences, engineering, and technology [6]. These technologies, including high pressure, electrical pulses, and ultrasound, are specially designed for economy, simplicity, and energy efficiency [7]. Generally, ultrasound (US) is used and referred to as high- and low-energy applications. When the frequency is between 20 and 100 kHz, it is known as high-energy ultrasound (greater than 1 Wcm\({}^{-2}\)) or low frequency.