Transcript Nanoscience Studies of Food Structures

Natural Food Nanostructures
1. Introduction
2. Naturally Occurring Food Nanosubstances and Nanostructures
2-1. Carbohydrates
2-2. Proteins
3. Nanoscience Studies of Food Structures
3-1. Starch : a partially self-assembled nanostructure
3-2. Interfacial protein networks :self-assembly and disassembly on processing
4. Designing Food Nanostructures
4-1. Designer Starches
4-2. Designer Nano foams and Emulsions
5. The Status Natural Nanostructures in Food
6. Conclusions
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 Food is an example of soft matter: it is a highly complex biological structures.
 The main constituents of foods are proteins, carbohydrates and fats.
 Microscopy provides a methods for visualising the actual structure if foods.
 Atomic force microscopy (AFM) has permitted the investigation of biological structure at the
sub-molecular level under more natural conditions.
 In this chapter the nature of certain natural food nano-sized substances and the natural
nanostructures they form will be described.
 This chapter will also discuss the likely status of new foods based on such approaches,
particularly in relation to the on-going debate on nanotechnology and food.
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“나노기술”이란 나노미터 크기(10-9m) 범주로 제조․가공하여 기존의 식품
이나 물질의 특성과는 다른 새롭거나 개선된 물리적, 화학적, 또는 생물학적 특성을
나타내도록 하는 기술을 말한다.(식품의약품안전청, 2012)
“나노기술응용식품”이란 식품의 제조․가공에 나노기술이 이용되거
나, 나노소재가 첨가된 식품을 말한다.(식품의약품안전청, 2012)
식품분야 나노입자크기
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Ingredients / Additives
 지방크기 작게 제조한 low fat ice cream (Nestle & Unilever)
 나노캡슐화된 Omega-3 DHA 첨가 (Nu-Mega Driphorm)
 양친매성 CoQ-10 (Pure Nutri-Nano)
 나노캡슐화된 수용성 cartenoid (BASF)
 SiO2, TiO2 (0.5~20 nm) 등을 이용한 나노코팅
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Naturally Occurring
Food Nanosubstances and Nanostructures
1.Carbohydrates
 The carbohydrates that are most responsible for strucring foods are polysaccharide.
 Polysaccharides are used as thickening and gelling agents in processed foods.
 Polysaccharides are generally high mole weight chain-like structures with diameters
typically a few nanometers in size. Thus they can be considered as naturally
Occurring nanosubstances.
 Understanding the native granular structure offers a route to the design or rational
Selection of new starches with unique of desired functional properties.
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Naturally Occurring
Food Nanosubstances and Nanostructures
2. Proteins
 Proteins are essentially high-molecular weight linear polymer composed of a chain of
amino acids.
 The globular proteins are generally tens of nanometers in size and the diameters of
rod-like proteins are a few nanometers in size. These molecules are also an example of
natural nanosubstances.
 Proteins are also used to stabilise foams and emulsions. This behaviour is determined by the
structures that are formed by the proteins at air-water and oil-water interfaces.
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Nanoscience studies of food structure
1.Starch: a partially self-assembled Nanostructure?
 Plants store energy in the form of starch. Starch is synthesised as partially crystalline,
spheroidal, granular structures.
 Granule structure, electron microscopy of granules and modelling of small X-ray(SAXS) and
angel neutron scattering (SANS) data on starch granules.
 The chemical structure of both amylose and amylopectin is based on a polymeric chain
composed of a-(1→4)-D-glucose, with the small amylosic branches of the amylopectin linked at
the 6-position of the glucose (a-(1→4,6)-D-glucose linkage points.
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Nanoscience studies of food structure
1.Starch: a partially self-assembled Nanostructure?
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Nanoscience studies of food structure
1.Starch: a partially self-assembled Nanostructure?
 Both high-resolution electron microscophy and interpreation of the SAXS data suggest
That the crystallites are nanocrystals, typically ~ 9nm in length .
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Nanoscience studies of food structure
1.Starch: a partially self-assembled Nanostructure?
 In starch-based food, both the amylose and amylopectin structures can recrystallise partially
on cooling storage.
 Starch-based material which survives transit through the stomach and small intestine and is
fermented in the colon is termed resistant starch (RS).
 The ability to visualise the nanostructure within starch offers the prospect of desinging,
modifying or screening for starches with enhanced functional and nutritional value.
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Nanoscience studies of food structure
2. Interfacial protein Networks : Self-assembly and Disassembly on processing
 AFM provides a means of visualising interfacial protein networks at the molecular level.
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