Boiling of potatoes
Introduction
Theory
Starch
https://clarissacagnato.weebly.com/starch-grain-analysis.html
- 2 organic polymers:large molecules composed of repeated sequences of units, attached by covalent chemical bonds).
- The structure of starch is made up of 2 different chains: linear helical amylase and branched amylopectin.
- Amylase is soluble. Linear chain
- amylopectin is insoluble. Massive branched molecule.
- Starch is located in most plant tissues, particularly in storage organs such as rhizomes, tubers, and grains.
Starch is stored in organelles called amyloplasts within plant cells. These amyloplasts convert glucose into starch and store it for later use. Some plant roots and embryos, in the form of seeds and fruit, also serve as storage units for starch.
Inside the amyloplast, these molecules do not float freely. They pack into organized semi-crystalline granules. The branched chains of amylopectin form the crystalline lamellae, creating a rigid skeleton that protects the plant's energy supply from premature degradation.
Leaf starch is highly dynamic and follows a strict diurnal rhythm. It accumulates during the light period and is depleted almost entirely by dawn to fuel growth and metabolism. Calvin Cycle. / Glucose-1-phosphate / ADP-glucose /
Thylakoid membrane
See also https://blogs.ubc.ca/biol343/the-plant-cell/
Parenchyma tissues of roots and tubers
Stroma
The stroma is the colorless, spongy cell matrix that supports the plant cell itself. In tubers, rhizomes and other starch-storing plant organs, it also acts as a place to store food for later use. When the plant needs the energy in the starch, it converts the starch grains back into glucose.
Read More: https://www.sciencing.com/where-is-starch-stored-in-plant-cells-12428011/
Starch grains inside potato cells (120x magn)
Potato starch contains typical large oval spherical granules ranging in size from 5 to 100 μm.
Potatoes: Highly efficient tuberous stems that utilize specialized cellular cavities to maximize starch density.
Starch gelatinization
- Granule swelling
- Melting of double helical structures
- Amylose leaching
Gelatinization
The cell walls get broken.