The monetary value of frozen food when cooking time is considered
760013 Susumu Morita
There exists a general conception that for college students living by themselves,it is more economical to cook meals than to buy and thaw frozen food, but if the time needed for cooking is considered, the problem is not so simple. Here I show that considering a college student’s expected earnings in the required cooking time, it is less economical to cook than to buy and thaw frozen food.The result indicatesthat college students don’tnecessarily have to strive to cook by themselves but can take advantage of the modern convenience if they want to live more economically.
The family budget of Japanese college students living by themselves is usually very tight1, and it is generally thought that cooking meals themselves helps reduce the expenditure, and that they should not rely on frozen food or restaurantsfrequently.However, the students are at the same time extremely busy studying, part-time working, and participating in club activities2, thus the time needed for cooking, in which they can work part-time and get some earnings, is also of great importance for them, and therefore whether cooking by themselves is more economical for college students is unclear.Frozen shrimp pilafis a suitablematerial forinvestigating this problem, asit is familiar in supermarkets and also its contents can be sorted and weighed separately, thereby enabling minute calculation of the price of its ingredients. To provide college students with a criterion for whether they should cook or buy and thaw frozen shrimp pilaf, approximately how much money is needed for the ingredients of shrimp pilaf, and how much earnings a college student can expect in the required cooking time must be calculated.
In this experiment, “SEIYU FINE SELECT Shrimp Pilaf,”whose ingredients appear on Table 1, was used as a material. Referring to this table and eight normal recipes of shrimp pilaf that appeared on internet search3-10, shrimp pilaf was cooked in the process which appears on Text 1.The wet weight of the ingredients of the shrimp pilaf before cooking (value A of Table 2,) the dry weight of the sorted contents of the cooked shrimp pilaf(value B of Table 2, Figure 1,) and the dry weight of the sorted contents of a pack of the frozen shrimp pilaf were weighed to 0.1 gram (value C of Table 2.) And the time the author, who has little experience in cooking, needed to cook shrimp pilaf was calculated in another trial. The time of leaving washed rice and boiling rice with a rice cooker was not included, based on the assumption that the time can be shifted and used for part-time working.
Text 1 | Process of cooking shrimp pilaf.
- Wash rice and leave it for 30 minutes.
- Chop onion, carrot, kidney beans, and pimento and slice mushrooms.
- Add rapeseed oil, corn, shrimp and 2 into a pan and fry them until the onion becomes transparent.
- Add 1 into 3 and season it with salt and pepper, and fry them until the rice becomes translucent.
- Add 4 and water into a rice cooker and boil it.
The results of weighing were as appear on value A-C of Table 2. First, using these data, the weight of the ingredients used in the frozen shrimp pilaf(value D of Table 2)was calculated from the equation D=A*C/B. Onion, rapeseed oil, chicken bouillon used in the frozen shrimp pilaf couldn’t be weighed, so their weight was estimated from the average of these ingredients per weight of rice used in the eight recipes4-11 (value E of Table 2.)Although various other ingredients are used in the frozen shrimp pilaf, their price issmall compared to those which appear on Text 1, and can be overlooked.Next, using data of average retail price in Japan11, the price of each ingredient of the frozen shrimp pilaf (value H and I of Table 2) was calculated from the equation H=D*F/Gand I=E*F/G (F=retail price, G=unit of retail price.)The total cost of the ingredients calculated in this way was 214.2 yen (bottom right of Table 2.)The time needed to cook shrimp pilaf was 13 minutes and 40 seconds, and according to a survey, the average earnings per hour of a college student working part-time was 1110.3 yen12. Therefore, if the time saved by using frozen shrimp pilaf was shifted and used for part-time working instead, an average college student could earn 252.9 yen (=1110.3(yen)*(13*60+40)(seconds)/(60*60)(seconds,)) which can be interpreted as the value of convenience of the frozen shrimp pilaf.The actual retail price of the frozen shrimp pilaf surveyed in Hamadayama branch store of SEIYU on July 15, 2007 was 396 yen, and 396-252.9=143.1(yen) was smaller than 214.2 yen. The result of calculation leads to a conclusion that for a college student it’s more economical to buy frozen shrimp pilaf and thaw it than to cook.
Although the conclusion of this study was as written above, it was based on assumptions generalizing various factors. Actually, the earnings of part-time working and the time required for cooking depends on the individual, and also the retail price of ingredients depends on the season, city, and store in which he or she shops. Moreover, ifthe pleasure of cooking or the issue of the safety of food is focused, it cannot simplistically be determined that frozen food is more desirable.This study focused only on shrimp pilaf, but if other frozen food is studied, the result may differ: the more complicated the food is, the more economical frozen food is expected to be, because of the long cooking time which could be saved in a factory.
Technology has always replaced what had been produced at home with industrial products since the Industrial Revolution, and the nearly-triple increase in the production of frozen food for household use in Japan in the last 20 years (Figure 2) indicates that food is not an exception. The result of this study shows that frozen food, even though more expensive than the ingredients of home-made food, significantly reduces the time required for preparing meals, thereby contributing to the economy of college students’ daily lives. In the times of aging and dwindling birth rate, the consumption of frozen food will increase not only among college students but also among ordinary households, as more and more workforce will come to be required to maintain the society.
1. Japan Student Services Organization. Results of the Survey on Students’ Lives in 16 of Heisei. last accessed on July 7, 2007.
2. Statistics Bureau of Japan Ministry of Internal Affairs and Communications. Basic Survey on Social Life in 13 of Heisei. last accessed on July 7, 2007.
3. last accessed on June 16, 2007
4. last accessed on June 16, 2007
5. last accessed on June 16, 2007
6. last accessed on June 16, 2007
7. last accessed on June 16, 2007
8. last accessed on June 16, 2007
9. last accessed on June 16, 2007
10. last accessed on June 16, 2007
11. Statistics Bureau of Japan Ministry of Internal Affairs and Communications. Results of Statistical Research on Retail Prices (17 of Heisei)
12. Intelligence Corporation. Survey on the Actual Situation of Part-time Working by High School and College Students 2006
13. last accessed on July 7, 2007
Acknowledgements The author wishes to thank Mr. Yu Wakabayashi for his help in cooking shrimp pilaf; and Mr. Tom Gally and Mr. Toru Oda for comments and valuable discussions.
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