COLUMN

●The Case of the Messed-Up Christmas Cake

At the end of last year, many children in Japan were looking forward to Christmas cake. On Christmas Day, the cake that arrived from the delivery company was opened and found to be a mess, disappointing many children. The department store that sold the cakes said at a press conference that of the 2,900 cakes it had manufactured, about 800 had lost their shape. The difference is that the freezing period after production was drastically shortened from two weeks last year to about one day this year due to a late arrival of strawberries from a poor harvest. However, he concluded that “it is impossible to identify the cause.

Wow~ I wonder if the food industry is allowed to just issue a letter of apology and a refund for a cake whose quality has been affected…

●Unknown cause?　That can’t be true.

If you were in the pharmaceutical industry, you would immediately understand. Don’t you think the food industry knows how to investigate the cause of deviations, which is common knowledge in the pharmaceutical industry?

It was the same as the manufacturing process last year. (In the case of pharmaceuticals, this means that the products were manufactured in accordance with the GMP manufacturing standards.)　Delivery was also made to the same supplier with the same refrigerated truck as last year. (In the case of pharmaceutical products, quality control is conducted in accordance with GDP, which is a quality assurance standard until the products reach medical institutions and patients.)

What caused the deviation?　Since few details have been reported on the cause of the messed-up cake, the author’s guess is that the cause of the quality deviation can be determined by depicting the manufacturing process of a Christmas cake as shown in Figure 1.

●Estimation of the cause of the deviation

Based on this estimated manufacturing process, we can estimate the cause of the deviation (Figure 2).

Christmas cakes are fresh products and must be kept frozen until the pinpoint delivery date of December 25. The cake is delivered from the cake factory to the customer in a frozen state by a delivery company’s cool courier service, and is then thawed and enjoyed at the customer’s home. This means that quality control is required to prevent quality deterioration and loss of shape when the customer tastes the cake. It has already been verified that the cakes do not lose their shape even during shaking during home delivery if they are frozen. The reason for the loss of shape can then be narrowed down to insufficient freezing.

・Strawberries were delivered just before the production date due to a poor harvest.

・Therefore, the freezing period was shortened from two weeks to one day.　　

The manufacturing method has been changed, hasn’t it?　The manufacturer’s comment that the manufacturing method has not been changed seems to indicate a lack of understanding of the freezing and preservation method.

●An experiment to estimate that insufficient freezing time is the cause of the problem

It may be true for one cake that one hour is enough time to freeze a cake. However, it is clear from the author’s experience in handling biopharmaceutical API that one hour is not enough time to freeze all of the 2,900 cakes packaged in paper boxes. (Figure 3)

The space in the decorative box containing the cake is insulated and conducts heat poorly. Furthermore, when these cakes are stacked in layers, it should take a long time for the cake in the center to freeze. In the experiment, the time lapse until the freezing of one cake in a paper box and the time lapse until the freezing of the cake in the center of the stacked cakes were imitated by cakes with insulation in the space of the paper box.

It took 1.2 hours to freeze a WFI (A in Figure 3) of the same weight (200 g) as the cake, but it took 4 hours to reach the set temperature of -30°C in the freezer. When one cake (200 g) was placed in a paper box and frozen under the same conditions (B in Figure 3), it took 0.8 hours to freeze, but it took 6.5 hours to reach the freezer’s set temperature of -30°C. When the cake was frozen with insulation in the space of the paper box (C in Figure 3), it took 2.5 hours to freeze and 21 hours to reach the freezer’s set temperature of -30°C

Incidentally, it is well known that when freezing pure water such as WFI, a “supercooling phenomenon” occurs in which there is no temperature change at 0°C and the temperature does not drop linearly.

When 2,900 cakes were piled up and placed in a freezer, the cakes in the lower center, where cooling heat is difficult to transfer, were shipped in a state of insufficient freezing for one hour, and it is estimated that the cakes were crumbled when they reached customers due to vibration during transportation by a refrigerated delivery truck.

●What is the biggest problem?

The fact that they made changes to the cake production procedure without adequate verification. If they had followed “change control,” which is common practice in the pharmaceutical industry, they would not have disappointed the children at Christmas.

The experiment conducted by the author was only an experiment to estimate the cause of the quality deviation, whether one day was sufficient to freeze 2,900 cakes. At the very least, a thermometer should have been placed in the lower center of the cakes, where the cooling temperature is not easily transmitted, when the 2,900 cakes were stored and frozen.

●Is it necessary for food products to be subject to the same level of quality control as pharmaceutical products?

The news about supplements containing red yeast rice (functional food), which have been in the headlines since April, has been causing some people to review the quality control system, partly because a fatality occurred. The following is a summary of the related news as of April 16:

1) The cause may be puberulic acid derived from blue mold,

 2) A part of the raw material that fell on the floor at the Osaka factory was used to produce red yeast rice,

 3) The Gifu Prefectural Health Center conducted an on-site investigation at the Gifu factory and reported no problem,

4) The Ministry of Health, Labor and Welfare and Osaka City conducted an on-site investigation at the Osaka factory and issued an order to recover the red yeast rice supplement and the health hazard as a causal relationship cannot be denied, 

the other hand, it was found that all of the people who died after taking red yeast rice malt supplements were undergoing treatment for prostate cancer, leukemia, etc., and it seems that it cannot be determined whether red yeast rice was the direct cause of death.

Side effects such as kidney dysfunction and death are the same as serious side effects in the case of pharmaceuticals. If such serious symptoms are suspected to be the cause of the appearance of such adverse reactions, even in the case of food, there will be growing calls for quality control comparable to that of pharmaceuticals. In contrast, if quality assurance is strengthened, there is a risk that the cost will be too high to be commensurate with the cost of food products. Functional foods are only foods, and must be strictly distinguished from pharmaceuticals that are expected to have medicinal effects. While I was writing this column, I received an outrageous news that “the main functional ingredient of red yeast rice supplements is a pharmaceutical product. (as of April 16)　 Since this is likely to develop into a very complicated issue, I will leave the rest of the story for the next column.