THE EFFECT OF VINEGAR IN DEGRADING POTATO

GLYCOALKALOIDS TOXIN – SOLANEN

Research Proposal CSP110NUniversity of Houston-Downtown

Minyi ChenMarch 30, 2012

GLYCOALKALOIDS Glycoalkaloids are a family of poisons

commonly found in the plant species Solanum dulcamara, the nightshade.

There are several potentially toxic glycoalkaloids, which is composed by alkaloids and sugars.

Solanine is a typical case of glycoalkaloid usually found in potato.

Reference, Johns,T.,and Keen,S.L. (1986). Taste evaluation of potato glycoalkaloids by the Aymara: A case study in human chemical ecology. Human Ecology, 14(4), 437-452.

SOLANINE In Potatoes, the glycoalkaloid (TGA)

poison - solanine naturally exist as the 6 kinds of solanidine derivant (Figure1 & Table1), which consists as much as 95% of the TGA fraction of alpha-solanine and alpha-chaconine. (Wood, F.A.,and Young, D.A. (1974). TGA in potatoes. Agric. Can. Publ.1533: pp. 1-2.)

composition

R1 R2 R3 molecular mass

α-Solanine galactose glucose rhamnose 867β- Solanine galactose glucose   721γ- Solanine galactose     559

α-chaconine.

glucose rhamnose   851

β-chaconine.

glucose rhamnose   705

γ-chaconine.

rhamnose     559

HOW SOLANINE OCCURS Generally speaking, solanine concentrated in

its leaves, stems, sprouts, and fruits. The highest concentrations of solanine occur just underneath the surface.

Potatoes that have been exposed to light in the field or during storage mechanical damage become green, due to an accumulation of chlorophyll.

portion TGA (mg/100g) FWwhole tuber 7.5 (4.3-9.7)

flesh 1.2-5skin 2-3% of tuber 30-60

peel 10-15% of tuber 15-30bitter tuber 25-80

peel from bitter tuber 150-220

* Wood, F.A. & Young, D.A. (1974). TGA in potatoes. Agric. Can. Publ.1533: pp. 1-2.

Table 2. Normal Levels of TGA in various tuber tissues

HOW SOLANINE AFFECT HEALTH Solanine poisoning is primarily displayed by

gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea,

vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, headache and dizziness. In more severe cases, hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils, hypothermia and death have been reported.

 Affected

 Potato type

 Quantity

Consume

d

Concentration of TGA mg/kg bw

Estimated

Toxicmg/kg bw

 Outcome

 Reference  

 56 (soldiers)

peeled, cooked

(whole,uncook

ed)

 1-1.5 kg

 24

(38)

 3.4-5.1

 recovered  Pfuhl,

1899

 60 adults 1 child

 potatoes

 500 g ? 200 g ?

 41

3.4

4.5 (lethal)

recovered1 fatal

(5 yr-old)

Harris & Cockbur,

1918

50-60

(Cyprus)

 shoots, leaves  ? 2749

 ?

 1 fatal

Willimot, 1933

 Prisoners

 experimental ?

 ?

 2.8

 recovered

Cited by Ruhl,1951

 4 (family adults)

 baked

potatoes with skin

1-3 potatoes

150-450 g

  50

 1.2-3.2

 dose-related,recov

ered

 Wilson, 1959

 78

schoolboys

  

old potatoes

 2 small

potatoes 200 g

  

25-30

  

1-4-1.6

3 comatose recovered;yo

ung boys,more affected

 McMilla & Thompson

,197961(school

-children)Alberta

 baked potato

 200 g

 49

 2.5

 recovered

 Anon.198

4

Table 3. Summary of published reports of solanine poisoning in humen

? Data ware not reported. Data from public reports. First draft prepared by Dr T. Kuiper-Goodman and Dr P.S.. Secondary by author

HOW TO DESTROY SOLANINE it is known that solanine can partly be destroyed

by some ways but mostly only effect a litter . Deep frying potatoes at 170°C (306°F) is known

to effectively lower levels because they move into the frying fat, whereas microwaving is only somewhat effective.

Freeze drying or dehydration has little effect Boiling has no effect. As a kind of base, acid (vinegar) can also reduce

the content of solanine in a certain extent, but the effectiveness still haven’t been clearly identified.

Review of Toxicological Literature prepared for Errol Zeiger, Ph.D, National Institute of Environmental Health Sciences, Submitted by Raymond Tice.Testing Status of Agents at NTP (National Toxicology Program). February 1998.

EXPERIMENT METHOD Treat with Vinegar in under different conditions

Part 1. Different concentration of Vinegar Part 2. Different cooking temperature Part 3. Different cooking time

Prepare Cut 3 large budded potatoes into equally small patches

and completely mix. Equally separate sample into two parts. One is group A with cutted, and group B is well mush.

Prepare tubes and label as 1A, 1B, 2A, 2B, e.g. Equally add 10g potato patches into each tube which

labeled as A, and 10g mushed into tubes with label B. Set potato mixture into groups as 3 tubes of cut and 3

mushed for each group.

Part 1.Different concentration of Vinegar Set gradient concentration of vinegar as 0.5mL, 1mL, 2mL,

3mL, 5mL. Add purified water 5mL to each tube and in the first 5 groups

with vinegar, and the last group with 3mL water. Water bath in 100 degree C for 10 min.

Part 2. Different cooking temperature With the result of part 1, choose the concentration of vinegar

which decomposes half of the solanine contained in potato. Set 3 groups with gradient temperature as 60 degree C, 80

degree C, and 100 degree C and one group with room temperature. Equally add vinegar to each tube

Water bath for 10 min.

Part 3. Different cooking time Set 4 groups with gradient time as 5 min, 10 min, 15 min, and

20 min. Add the same amount of vinegar as part 2. Water bath in 100 degree C.

GET THE RESULT Extraction Solanine

Ethyl alcohol-Acetic acid method (Double-solvent method) with the most efficient way—by setting the ratio of Ethyl alcohol and Acetic acid in 100:30.

Measure the Concentration of Solanine High Performance Liquid Chromatography

(HPLC)