Monday, November 2, 2009

Introduction
There are a lot of people who love to have French fries. There are also a lot of people trying to fry their own home made French fries. Some of them manage to get a pretty good outcome, while some are having a bad mood from their home made French fries. Some people might have know a magic trick on how to fry their French fries and having a good outcome instead of having a sticky French fries and also a brown French fries that looks like overcooked. In this blog, we try the magic trick and evaluate how this trick can affect our French fries. The source of this method came from a friend saying that soaking potato into the cold water with vinegar will increase the crispiness of the French fries and at the same time soaking the potato inside it will help prevent the browning effect on the potato.This is a method which the source was get from a friend saying that soaking potato into the cold water with vinegar will increase the crispiness of the french fries and at the same time soaking the potato inside it will help prevent the browning effect on the potato.

The Preparation
1. Potato is cleaned and washed

2. Cut into desired pieces and soak the potatoes strips inside the bowl which contain cold water and vinegar.
soak into water with vinegar(up), without soaking(down).

3.Squeeze it softly and leave it for 30 minutes.
Soaking after 30 minutes(up), without soaking after 30 minutes(down)

4. Drying

5. Frying.

6. After frying
Fries that was soaked (up), and fries that without soaking (down).

Result
As from the result we can observed that the potato that was soaked inside the cold water with 3-4 spoon of vinegar helps to prevent the maillard reaction on the potato and this help the potato stored longer before frying and thus it help maintain the whiteness appearance of the potato which looks good on it. After frying, the fries that was soaked is a bit light brown compared with the without soaked fries which is darker brown. Besides that the fries that was soaked with vinegar has a bit of sweet and sourness which is quite nice. As for the texture, the soaked fries is more crispy than the without soaked one.

THE SOAKING
The soaking was able to remove excess starch from the potatoes strips and so that the potatoes strips do not stick together during frying. Beside that putting vinegar into the water will lower the pH of the water and this would block the nucleophilic addition of asparagine with a carbonyl compound, preventing the formation of the corresponding Schiff base, a key intermediate in the Maillard reaction and in the formation of acrylamide (Jung et al.2003)(Kita et al.2004)(Pedreschi et al. 2007)(Rydberg et al.2003).

What cause it Crispy??
The development of an externally oily and crispy crust is a major of transformation occurring during frying of potatoes due to high temperature and oil infiltration (Pedreschi et al. 2004). By softening of the middle lamella between cells, starch gelatinization inside cell and dehydration crust formation in fried potato is the result changes of the original of the potatoes tissue after exposure to hot oil.The higher frying temperature accelerated cooking of core and hardening of the crust and a finish fried potato strip became a composite structure made of a hard crust region and a soft core region (Pedreschi et al. 2004).

THE MYTHS BEHIND THE FRYING
The potato is best known for its carbohydrate content. The predominant form of this carbohydrate is starch. However, carbohydrate-rich food like potato will easily form acrylamide when it was fried or baked under high temperature.Especially when potato is used to make french fries where the potato need to undergoes deep fried. Acrylamide is a suspected carcinogenic to human and is still undergoes various studies about it. It formation pathway is link with the Maillard reaction and is was believe that it was the by product of the reaction. The free amino acid asparagine and reducing sugar are consider as the precursor (Stadler et al. 2004).The acrylamide level is greatly depend on the on the cooking condition and can be observed as the fries will be more browning if the level of acrylamide is high (Lauren et al. 2005) .

References
Jung et al., 2003 M.Y. Jung, D.S. Choi and J.W. Ju, A novel technique for limitation of acrylamide formation in fried and baked corn chips and in French fries, Journal of Food Science 68 (2003), pp. 1287–1290

Kita et al., 2004 A. Kita, E. Bråthen, S.H. Knutsen and T. Wicklund, Effective ways of decreasing acrylamide content in potato crisps during processing, Journal of Agricultural and Food Chemistry 52 (2004), pp. 7011–7016.

Rydberg et al., 2003 P. Rydberg, S. Eriksson, E. Tareke, P. Karlsson, L. Ehrenberg and M. Törnqvist, Investigations of factors that influence the acrylamide content of heated foodstuffs, Journal of Agricultural and Food Chemistry 51 (2003), pp. 7012–7018.

Stadler et al., 2004 R.H. Stadler, F. Robert, S. Riediker, N. Varga, T. Davidek and S. Devaud et al., In-depth mechanistic study on the formation of acrylamide and other vinylogous compounds by the Maillard reaction, Journal of Agricultural and Food Chemistry 52 (2004), pp. 5550–5558.

Pedreschi et al., 2004 F. Pedreschi, K. Kaack and K. Granby, Reduction of acrylamide formation in potato slices during frying, LWT – Food Science and Technology 37 (2004), pp. 679–685

Lauren S,J. F. Al-taher, Effects of Consumer Food Preparation on Acrylamide Formation, Chemistry and Safety of Acrylamide in Food (2005), pp. 447-465