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SPECIAL FOCUS
SPECIAL FOCUS
Removal Chemical from Vegetables

and Fruits with Fine-Bubble Technology

It’s well known that vegetables and fruits are typical supply source of
important nutrient such as vitamins, fibers and minerals. Consumption
of vegetables and fruits provides many benefits to human body, for example,
to adjust cholesterol level in the body by fiber absorbing excess cholesterol and
discharging from the body, and the natural enzymes contained in vegetables and fruits
help better digestion of human body.

These days, health conscious consumers are body and liquid that make bubbles shrinked and cause
increasing. They would like to eat more vegetables self-pressurization. Microbubbles reduce diameter to be
and fruits daily, however, according to a survey nanobubbles (Figure 2) by compressing the gaseous body
from The Thailand Pesticide Alert Network (Thai- and making internal pressure increase continuously to be infinity before
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PAN), over 60% of popular vegetables sold in Thai disappeared . Self-Pressurization inside the bubbles can be explained theoretically by
market are contaminated with a cocktail of pesticides Young-Laplace’s law.
that farmers use to boost yields and ensure year-
round sales . Organic vegetables are available in : Change of inside pressure
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the market but those are high in price due to low : Surface tension
harvesting capacity. Thus, consumers, supplier and D : Diameter of bubble
food manufacturers would try to reduce remaining Smaller bubbles have higher inside pressure than the bigger bubbles. So, they are
pesticides in the ordinary produces. Some chemicals able to remove dirty including pesticide residue. Therefore, the fine-bubble technology can
or detergents are sometimes proposed to use for reduce not only dirty but also the risk of pesticide consumption for better human being.
washing vegetables and fruits. Recently Fine-Bubble
technology has been recommended to wash them เอกสารอ้างอิง/Reference
more effectively. 1 Penchan Charoensuthipan. 2017. 64% of veggies ‘unsafe’ due to pesticides. Available at
There are many researches about the www.bangkokpost.com/news/general/1366435/64-of-veggies-unsafe-due-to-pesticides.
Temesgen, T., Bui, T.T., Han, M., Kim, T., Park, H. Micro and Nanobubble technologies as new horizon
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effectiveness of fine-bubbles. And the fine-bubbles for water-treatment techniques. Advances in colloid and interface science 246: 40-51.
have been practically used for several objectives 3 Agarwal, A., Ng, W.J., and Liu, Y. 2011. Principle and applications of microbubble and nanobubble
including washing and cleaning . Fine-bubbles are technology for water treatment. Chemosphere 84(9): 1175-1180.
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defined diameter to be less than 100 µm, and of
which, diameter of bubbles from 100 µm to 1 µm
is called as microbubble, and diameter of bubbles
from 1 µm to nanosize (100 – 200 nm) is called
nanobubble.
Normally, bubbles in water receive hydraulic
pressures perpendicularly from all directions as
Figure 1. And buoyance is cause by difference
between the sum of upward and downward pressures
to the bubbles. According to Archimedes’ principle,
in the water, matter receives buoyance equivalent
to mass of water that matter submerge. Normal size
bubbles receive high buoyance so bubbles will rise
to the surface in short time and have no time for
shrinking by effect of surface tension.

รูปที่ 2 ชนิดของฟองอากาศ
Figure 2 Different types of bubbles
Thus, the fine-bubbles, which diameter is smaller
than normal-bubbles, are received lower buoyance,
bubbles will slowly rise to the surface. The fine-
bubbles will stay longer in the water and receive
surface tension at interface between gaseous

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