Tangential microfiltration of orange juice in bench pilot

Abstract

SUMMARYThe aim of this study was to introduce the tangential microfiltration (TMF) technique on the production of orange juice (TMFJ), and compare it with pasteurised juice (control) as regards chemical composition and sensorial characteristics. We used a TMF pilot equipped with four monotubular ceramic membranes (0.1, 0.2, 0.8 and 1.4µm) arranged in series with a filtering area of 0.005 m 2 each. Commercial flash-pasteurised orange juice was used as the initial product. Experiments were divided into three parts: a) the characterisation of the TMF pilot; b) optimisation of operational conditions; c) production of the TMFJ. In the second part, membrane with 0.8-µm pores presented best flux followed by those with 1.4-, 0.1-, and 0.2-µm pores. However, to guarantee permeate sterility, we chose the membrane with 0.1-µm pores for TMFJ production. Initially, the orange juice was sieved in order to separate part of the pulp, being subsequently submitted to TMF. A mixture of retentate and pulp was made, and was subsequently pasteurised. We obtained the TMFJ by adding the permeate to the mixture. TMFJ presented soluble solids content (°Brix), pulp, pH, and titrable acidity similar to the initial pasteurised juice (control). Nevertheless, 28% of vitamin C was lost during the TMFJ production. According to the juice taster panel, the control juice presented best sensorial characteristics (greater aroma intensity and fruity flavour) when compared with the TMJF.

Wine clarification from Spondias mombin L. pulp by hollow fiber membrane system

“…Protein content in permeate increased with operation time and in concentrate was fixed, but these behaviors changed after 80 or 120 min (for 0.60 and 0.40 bar, respectively) of process, in concentrate the protein content increased and was fixed in permeate, this effect is called fouling, while the membrane pores are obtruded. Thus, a constant rate of proteins passed into the pores by action of pressure, and the majority of protein contents on the membrane surface are dragged by concentrate flux, increasing the protein concentration in concentrate [16,17].…”

“…The plant, with a 2 L feed tank, was equipped with a polysulfone hollow fiber membrane module with a filtration area of 0.03 m 2 , an average pores diameter of 0.1 mm, a range of operating pressures (transmembrane pressure) of 0.4-0.6 bar, operating at room temperature and pH 4.5 [1][2][3][4][5]16,17]. A scheme of the MF system is depicted in Fig.…”

“…Finally the system was rinsed with tap water for at least 20 min. After each cleaning treatment the permeability of the membrane module under fixed conditions (temperature of 27 8C; axial velocity of process operation) was measured with water [1,5,16,17]. The permeability is used to perceive if the membrane module become to the initial condition.…”

Preservation and processing of tropical and subtropical fruits

“…Most of the work carried out on membrane processing refers to apple juice; however, several authors have reported its use with other tropical fruits such as pineapple (Jiraratananon et al , 1997;Vaillant et al , 2001;Carneiro et al , 2002;Barros et al , 2004), acerola (Matta, 1999;Barros et al , 2004;Wang et al , 2005), camu-camu (Rodrigues, 2002), guava (Chan and Chiang, 1992;Chopda and Barrett, 2001), orange (Hernandez et al , 1995;Venturini Filho et al , 2003), mango (Vaillant et al , 2001), passion fruit (Jiraratananon and Chanachai, 1996;Vaillant et al , 1999;Vaillant et al , 2001), watermelon (Miranda, 2005), tamarind (Watanabe et al , 2006), tangerine (Chamchong and Noomhorm, 1991;Vaillant et al , 2001) and umbu (Bruyas, 2004;Watanabe et al , 2006b). Table 11.8 presents some applications of membrane technology for tropical fruit juices.…”