Effect of thermal Processing Time on the Physicochemical and Sensory Properties of Lebanese Tfayfiha Verjuice Variety

Abstract

Verjuice is an unfermented, acidic, and sour-tasting juice abundant in beneficial bioactive compounds obtained from the mechanical pressing of unripe grapes. The effect of prolonged traditional thermal processing (for 0, 0.5, 1, 2, 3, 4, and 5 hours) on the physicochemical properties of 'Tfayfiha' verjuice was investigated. Polyphenol content and antioxidant capacity increased reaching their maximum (8348.6 mg/L) at 4 hours and (77.30%) at 3 hours respectively; indicating that the ideal processing time to obtain a nutritious functional food ingredient with high bioactivity is between 3-4 hours. At 5 hours, verjuice had the lowest pH (1.09), lowest moisture content (26.94%), and thus the highest shelf-life, density (1.187 g/mL), soluble solids content (60.06°Brix), color intensity, and sensorial scores on the preference test. Caloric content was below detection limits (in all samples) and thus neglected. Verjuice boiled for 1 hour can be used as an excellent alternative to fresh lemon juice, where only 16.6% of the participants recognized the difference in taste between tabbouli made with fresh lemon juice and that made with verjuice boiled for 1 hour. It can be concluded that different virgins of verjuice could possibly be released to the Lebanese market by changing waste unripe grape during thinning period into a valuable product.

Utilization of the basket press method to extract verjuice

“…Verjuice (or verjuis or agraz) is the unfermented juice of unripe green grapes obtained by direct pressing (Karabiyikli & Öncül, 2016). Verjuice has been evaluated for the treatment of hyperlipidemia and hypertension (Gutiérrez-Gamboa et al, 2021), inflammatory markers (Ahmadi et al, 2019;El-kaderi et al, 2020), and atherosclerosis (Shakir & Rashid, 2019). The verjuice has a specific sour/tart taste (de Matos et al, 2017;Kaya & Unluturk, 2019).…”

Physico‐mechanical properties of unripe grape berries relevant in the design of juicing machine

“…In recent years, in Western countries, this product has been considered as an asant flavor maker (de Matos et al, 2017;Nikfardjam, 2008). In traditional medicine, verjuice has been evaluated for the treatment of hyperlipidemia and hypertension (ZibaeeNezhad, Mohammadi, Babaie Beigi, Mirzamohammadi, & Salehi, 2012), inflammatory markers (Ahmadi, El-Kubbe, & Roney, 2019;El-kaderi, Tlais, Alkhatib, & Hamdan, 2020), and atherosclerosis (Alipour, Davoudi, & Davoudi, 2012;Mousa-Al-Reza, Ziba, Zakieh, Rad Tania, & Mohammad-Mahdi, 2011;Zolfaghari, Kazemi, & Nematbakhsh, 2015).…”