A Clear Can With Resealable Cap

clear plastic can with aluminum lid

Oh! A different packaging. On the second thought, it is not. It is basically modified from the idea of infant formula. A can with an easy open lid by pulling a small ring. Then can be sealed back easily by an extra plastic cover. It is not a foolproof way to prevent product spoilage after opening, but it gonna extend the edibility for some time. Continue reading “A Clear Can With Resealable Cap”

Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Accepts coaching and consultancy services. Lecturer of Cocoa Foundation of the Philippines.

Experiment: The Bulging Juice Aluminum Pouch

Package good such as sardines, coke in can and juice in pouches may bulge or bloat through the course of its shelf life. Such maybe due to anaerobic gas producing bacteria or reaction of food components to container – the case of acid to metal reaction.

All cans for food use are lacquered or coated with non-reactive enamel. It prevent any unnecessary migration of metal to food and or any unwanted process.

Bulged aluminum pouch is a rare scene. I have encountered it only twice. As stated above, the cause maybe microbial or chemical. I setup a simple experiment to verify that acid to metal reaction may cause container bulging.

I secured three empty juice pouches. Cut off the top, cleaned and dried. Poured with equal amounts of vinegar. Added equal sizes aluminum strip on each container. Sealed and set aside for later observation.

empty open pouchesAluminum strips were prepared by cutting a portion of aluminum pouch. Then sanding the inner side to expose the aluminum layer.

aluminum pouch stripspouches initialSlight bloating were observed on three trials after approximately two months. The observation continuous…

pouches slightly bloatedReaction speed in many commercial juices are rather slow due to their very low acidity.

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Go and read the update, Pouch Bulging Experiment | The Update.

Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Accepts coaching and consultancy services. Lecturer of Cocoa Foundation of the Philippines.

Reaction of Salt to Unknown Plastic Container

I was going to eat balut. I got pinches of salt and placed it on saucer. Then… It was a coincidence, I placed the open jar near my nose. The smell was disagreeable. Seems the smell of melting plastic.

salt and spoon in plastic jarHere are the other details.

It is a clear plastic jar with a yellow plastic screw cap. It is a brittle packaging. It’s the common packaging of Baguio’s peanut brittle. No recycling symbol embossed on both clear container and cap so its identity is unknown. Maybe it is a recycled plastic not fit for food applications.

We have been using the plastic jar for several years. A disposable plastic spoon is in the jar as permanent tool for getting salt.

I noticed the putrid aroma only after several years. It’s time to get a replacement jar and I will never get a jar of the same type. A glass or a polypropylene jar will do.

This is the first time I encountered salt affecting plastic containers. I tried searching around the web for answers. Never found any though. Maybe salt really reacted to plastic or to disposable plastic spoon alone after several years of contact.

This jar and the plastic jars of popular water sticks have the same appearance and texture, both clear and brittle. The latter has recycling code number 3, PVC. Maybe the first is polyvinyl chloride too. See “Wafer Sticks in PVC container“. If the first is a real PVC then the “chloride” words in both names make sense.

The two common food to container reactions. Metals such as tin and aluminum to acid foods and oily products to polystyrene polymers,”What if Tin Can and Aluminum Can Have No Lacquer Coatings?” and “Migration of Styropor to Food

Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Accepts coaching and consultancy services. Lecturer of Cocoa Foundation of the Philippines.

What if Tin Can and Aluminum Can Have No Lacquer Coatings?

Every inner of tin can and aluminum can is coated with protective lacquer. It protects the metal from corrosion and eventual destruction. Protects the food contents – contact of acid foods with metal causes the metal corrosion. Some metals are being absorbed into food causing off-taste, disagreeable odor and or change in color. And ultimately, protects the consumer from consuming potentially harmful food stuffs.

What if cans are not lacquered? How does it looks like when filled with organic acid?

I gathered two can representatives. One aluminum can and one tin can. I removed the top of aluminum can by cutting it with a sharp knife. Tin can cover was opened using a regular can opener. Lacquer coatings were removed by rubbing it vigorously it with industrial type sand paper. Rinse with tap water then filled with vinegar, about 1/4 of the container capacity.

tin can before vinegarI chose vinegar as representative of acidic foods. Results maybe slightly different with other food acids. I am going to do more test later.

After about three hours, a distinct brown to dark brown discoloration was evident around vinegar surface and the metal surface below the line got darker. Vinegar odor became slightly disagreeable.

tin can after vinegarAluminum can exhibited change only after three days. Vinegar to acid reaction seemed too fast. It might be as fast but with no visible signs. The part around vinegar surface showed numerous block dots. Aluminum soaked in acid got a cleaner look.

aluminum can after vinegarChanges above might actually happen to foods if the lacquer is defective, lacquer which contains pinholes. Gonna do a verification test with pinholes.

update as of May 15 2012 for tin can … After several days, the corrosion around the vinegar surface was more pronounced.  The space above also showed signs of rusting.  The cloudy vinegar became clear and few rainbow flakes were visible on surface.

tin can rusting

Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Accepts coaching and consultancy services. Lecturer of Cocoa Foundation of the Philippines.

Is Using Aluminum Cookware Dangerous?

Aluminum cookwares are popular because it conducts heat fast and even, lower cost and easier to produce, not prone to rusting and light weight.

Many never want to use it because: It reacts to acid and other foods such as tomato sauce, vegetables, fruits, vinegar, salt and egg. It is soft, easily got dents, scratches and softens at high temperatures. May cause off taste to prepared dish. And, might cause health problems.

Anodized aluminums are resistant to acid and might be a better option. However, scratches also makes it vulnerable.

Aluminum was believed to cause Alzheimer’s disease. It was reported that many people died of the disease had high levels of aluminum in brains. In contradiction, the high levels might be due to the disease itself, encouraging the deposition of excess amounts.

According to WHO, safe aluminum ingestion is 50mg per day. Aluminum is a popular ingredient of over-the-counter tablets ranging from 10 to 20 mg. Earth has aluminum, water has, plants and animals we it have it too.  Scary! Taking three tablets a day can mean ingestions of 60mg.

Cooking all foods in uncoated and non-anodized aluminum pots may expose one to more levels. Storing foods in it for prolonged periods will cause more migration, causing more dangers and damage to pan.

Aluminum not only gets into food chemically. Friction created by two colliding metals causes wear and tear e.g. cooking ube halaya in tulyasi and mixing it with aluminum ladle. The ladle gets smaller and the tulyasi gets thinner after long repeated use.

In a wider perspective, all metals are going to react to acidic foods. Different elements and alloys will react differently – stainless steel pot being the less reactive. Even the Teflon coated cookwares are not exempted. It should be used within its specified temperature limit and should not have scratches, otherwise, food will be exposed to melted Teflon and or metal.

On the contrary, it might be beneficial in small quantities. Magnesium and iron are essential elements.

Are we still using aluminum cookwares? Yes, we are but not for cooking acidic foods such as paksiw and sinaing na tulingan. New aluminum pot is shiny silver and gets off-white to slightly brown after several use. It gets to original color finish when cooked with acid foods. It bothers me. Its like cooking and dish washing in one.

Marvin is the lead chocolate maker of Ben and Lyn Chocolate Inc. Has strong background in food research and development. Occasionally conducts training and lectures. Accepts coaching and consultancy services. Lecturer of Cocoa Foundation of the Philippines.