Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling

Non-carbonated fruit juices often tend to foam over during bottling. The resulting foam height corresponds to the equilibrium of foam formation and decay. Therefore, the foam unexpectedly occupies more space in the bottle and carries parts of the juice out of the bottle, resulting in product loss un...

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Main Authors: Julian Thünnesen, Bernhard Gatternig, Antonio Delgado
Format: Article
Language:English
Published: MDPI AG 2021-09-01
Series:Eng
Subjects:
Online Access:https://www.mdpi.com/2673-4117/2/3/23
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author Julian Thünnesen
Bernhard Gatternig
Antonio Delgado
author_facet Julian Thünnesen
Bernhard Gatternig
Antonio Delgado
author_sort Julian Thünnesen
collection DOAJ
description Non-carbonated fruit juices often tend to foam over during bottling. The resulting foam height corresponds to the equilibrium of foam formation and decay. Therefore, the foam unexpectedly occupies more space in the bottle and carries parts of the juice out of the bottle, resulting in product loss under filled containers and hygienic problems in the plant. Chemical antifoams are likewise undesirable in most cases. Recent ultrasonic defoamers are effective but only capable outside the container and after the filling. In this article, a lateral ultrasonication through the bottle wall with frequencies between 42 and 168 kHz is used in-line for non-invasive foam prevention during filling. Foam formation during hot bottling of orange juice, apple juice, and currant nectar at 70 °C happens at flow rates between 124–148 mL/s. The comparably high frequencies have a particular influence on the fresh foams, where a large fraction of small resonant bubbles is still present. Foam volume reductions of up to 50% are reached in these experiments. A low power of 15 W was sufficient for changing the rise of entrained bubbles and minimizing the foam development from the start. The half-life of the remaining foam could be reduced by up to 45% from the reference case. The main observed effects were a changed rise of entrained bubbles and an increased drainage.
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spelling doaj.art-8f6d0a29f072446db05ef3063af8eddf2023-11-22T12:56:28ZengMDPI AGEng2673-41172021-09-012335637110.3390/eng2030023Ultrasonic Effects on Foam Formation of Fruit Juices during BottlingJulian Thünnesen0Bernhard Gatternig1Antonio Delgado2Institute of Fluid Mechanics, Friedrich-Alexander University Erlangen-Nuremberg, Cauerstr. 4, 91058 Erlangen, GermanyInstitute of Fluid Mechanics, Friedrich-Alexander University Erlangen-Nuremberg, Cauerstr. 4, 91058 Erlangen, GermanyInstitute of Fluid Mechanics, Friedrich-Alexander University Erlangen-Nuremberg, Cauerstr. 4, 91058 Erlangen, GermanyNon-carbonated fruit juices often tend to foam over during bottling. The resulting foam height corresponds to the equilibrium of foam formation and decay. Therefore, the foam unexpectedly occupies more space in the bottle and carries parts of the juice out of the bottle, resulting in product loss under filled containers and hygienic problems in the plant. Chemical antifoams are likewise undesirable in most cases. Recent ultrasonic defoamers are effective but only capable outside the container and after the filling. In this article, a lateral ultrasonication through the bottle wall with frequencies between 42 and 168 kHz is used in-line for non-invasive foam prevention during filling. Foam formation during hot bottling of orange juice, apple juice, and currant nectar at 70 °C happens at flow rates between 124–148 mL/s. The comparably high frequencies have a particular influence on the fresh foams, where a large fraction of small resonant bubbles is still present. Foam volume reductions of up to 50% are reached in these experiments. A low power of 15 W was sufficient for changing the rise of entrained bubbles and minimizing the foam development from the start. The half-life of the remaining foam could be reduced by up to 45% from the reference case. The main observed effects were a changed rise of entrained bubbles and an increased drainage.https://www.mdpi.com/2673-4117/2/3/23ultrasound applicationglass bottlesfruit juicefoam drainagefoaming behavior
spellingShingle Julian Thünnesen
Bernhard Gatternig
Antonio Delgado
Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
Eng
ultrasound application
glass bottles
fruit juice
foam drainage
foaming behavior
title Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
title_full Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
title_fullStr Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
title_full_unstemmed Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
title_short Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
title_sort ultrasonic effects on foam formation of fruit juices during bottling
topic ultrasound application
glass bottles
fruit juice
foam drainage
foaming behavior
url https://www.mdpi.com/2673-4117/2/3/23
work_keys_str_mv AT julianthunnesen ultrasoniceffectsonfoamformationoffruitjuicesduringbottling
AT bernhardgatternig ultrasoniceffectsonfoamformationoffruitjuicesduringbottling
AT antoniodelgado ultrasoniceffectsonfoamformationoffruitjuicesduringbottling