Unhygienic sugarcane juice can pose risks of bacterial imbalance, stomach pain, and digestive disorders for those who consume it.
Buying sugarcane juice by the liter to store in the refrigerator for later consumption might seem like a very economical choice: A 500 ml cup of sugarcane juice (half filled with ice) costs 10,000 VND. However, a liter of sugarcane juice concentrate only costs 25,000 VND. With one liter of concentrate, you can make four cups of iced sugarcane juice, saving you 15,000 VND.
It turns out that street-side sugarcane juice vendors in Vietnam are running an indefinite discount program of up to 37.5%—higher than discounts from Amazon, Walmart, and Best Buy during the biggest shopping holiday, Black Friday.
Who wouldn’t be tempted by such an unbeatable discount? 20,000 VND for two cups of sugarcane juice, or just an extra 5,000 VND for four cups? Clearly, choosing sugarcane juice by the liter is more economical.
With discounts surpassing Black Friday, many believe buying sugarcane juice by the liter is a smart choice.
However, many who have bought sugarcane juice this way have regretted it, as just one night in the fridge can turn the whole bottle sour, brown, and undrinkable.
If you’ve experienced this, you need to know where you went wrong.
I took my sour sugarcane juice bottle back to the vendor and received the reply: “You need to keep the sugarcane juice in the freezer; I can’t guarantee it if you leave it in the fridge.”
Indeed, that is how to preserve the shortest shelf-life beverage on Earth: sugarcane juice.
The shelf life of sugarcane juice is… 45 minutes
The reason sugarcane juice spoils quickly is due to two conditions that accelerate fermentation: First, a high concentration of microorganisms. Second, the presence of sugar.
A study published in the East and Central African Journal of Pharmaceutical Sciences found that fresh, unsterilized sugarcane juice from street vendors could contain up to 25 species of bacteria and 23 species of fungi (15 species of yeast and 8 species of mold).
The number of bacteria ranged from 1.44×105 to 6.0×105 cfu/ml (colony-forming units per milliliter), and the number of fungi ranged from 1.36×105 to 2.64×105 cfu/ml—exceeding the regulatory limits by 10 to 100 times.
The sources of bacteria and fungi in sugarcane juice may come from soil residues or even unwashed feces on the sugarcane stalks. They may also originate from the crushing machine, collection containers, filter cloths, or ice.
Additionally, the hands of the sugarcane pressers, flies, and the cups used also pose risks of cross-contamination for fresh sugarcane juice, as warned by scientists.
The street-side sugarcane juice extraction process is unhygienic, creating conditions for microorganisms to thrive and spoil the juice.
The presence of these microorganisms, especially yeast, accelerates the fermentation process of sugar, as indicated in the following chemical equations:
C12H22O11 + H2O + enzyme → 2 C6H12O6
C6H12O6 + 2 ADP + 2 Pi + 2 NAD+ → 2 CH3COCOO− + 2 ATP + 2 NADH + 2 H2O + 2 H+
CH3COCOO− + H+ → CH3CHO + CO2
CH3CHO + NADH + H+ → C2H5OH + NAD+ C2H5OH + O2 → CH3COOH + H2O
The products obtained from the fermentation of sugar in sugarcane juice include pyruvic acid (CH3COCOO−) and acetic acid (CH3COOH), which are responsible for the sour taste of old sugarcane juice.
Meanwhile, the browning of sugarcane juice is due to the activity of Polyphenol oxidase (PPO) enzymes, similar to the browning processes of fruits such as apples, pears, or avocados.
The rate of browning and fermentation in sugarcane juice depends on many conditions, such as temperature, pH, and the concentration of bacteria and fungi present in the juice.
The following are images of fermented sugarcane juice after 3 hours and 7 hours at room temperature (30±5°C).
A study published in the journal Sugar Tech by Indian scientists (a country that uses 21% of its agricultural land solely for sugarcane cultivation and then seeks ways to preserve it) indicated:
“The fermentation of sugarcane begins immediately after its juice is extracted. Enzymatic and harmful bacterial reactions will cause fresh sugarcane juice to turn brown and sour within hours if not properly stored, posing a potential health risk to consumers.”
In another study published in the International Journal of Food Properties, researchers quantified the estimate of “a few hours” through experiments and found that fresh sugarcane juice spoils within 3-5 hours at room temperature (30±5°C) and 8 hours in the refrigerator (4±2°C).
Sugarcane WNY, a sugarcane juice business based in New York, USA, even reported that fresh, pure juice extracted from sugarcane stalks will become unfit within 15 minutes at room temperature.
After 45 minutes, your sugarcane juice will be “expired.” It may not be spoiled yet, but it no longer qualifies as “fresh” juice straight from the machine.
“We recommend consumers drink fresh sugarcane juice immediately after it is extracted to achieve the best quality. If you want to slow down the oxidation process, you can squeeze some lemon into your juice or drink it with ice,” said Sugarcane WNY.
If you see calamondin added to the sugarcane juice, it’s not solely for flavor.
How to properly store sugarcane juice?
Indeed, if you’ve ever seen street vendors squeezing calamondin or lemon with sugarcane, it’s not just to enhance the flavor. The reason is that calamondin and lemon contain a lot of citric acid, which has been shown to lower pH and prevent the oxidation reaction of sucrose (C12H22O11), thus slowing down the fermentation process.
Ginger is also a common spice added to sugarcane juice. Scientific studies have shown that ginger contains many compounds such as 1,8-cineole, linalool, eugenol, and thymol—all of which have antibacterial properties.
Experiments by Indian scientists indicated that by pasteurizing sugarcane juice at 72 degrees Celsius and then adding lemon and ginger in a ratio of 3 ml and 0.6 ml per 100 ml of sugarcane juice, the shelf life in the refrigerator could be extended from 8 hours to 1 week.
Blanching raw sugarcane for 12 minutes at 100 degrees Celsius can reduce the browning of sugarcane juice. (Photo: Scientific Research Journal, Can Tho University).
In Vietnam, a study by Can Tho University theoretically confirmed that adding citric acid to sugarcane juice while blanching the raw sugarcane for pasteurization can prolong the storage time of sugarcane juice—especially, this can help prevent browning, preserving a more appealing color.
Combining a pasteurization process at 126 degrees Celsius for 10 minutes, followed by adding citric acid and sodium metabisulfite (SO2) at a concentration of 0.1%, can extend the shelf life of sugarcane juice in the refrigerator (at 4 degrees Celsius) up to 105 days (or 15 weeks), according to a study published in the journal Sugar Tech.
Using the method of adding citric acid to lower pH, followed by pasteurization and then gamma irradiation to eliminate microorganisms in sugarcane juice, scientists have even been able to extend the shelf life of this beverage at room temperature from 3 hours to 60 days.
Additionally, researchers have explored various methods to increase the shelf life of sugarcane juice, from wrapping it in nano films, applying electric pulses, to infusing sugarcane juice with ozone…
However, as you can imagine, most of these methods require chemicals or expensive equipment. They are typically only applied in industrial settings—targeted at businesses looking to produce, can, or export sugarcane juice.
For consumers, a person just stopping by a street vendor, purchasing a one-liter bottle of sugarcane juice, and putting it in the refrigerator, the best and simplest preservation method remains to put the entire bottle into the freezer.
After one night (12 hours), the sugarcane juice in the refrigerator (left) has turned brown, losing its fragrance, while the sugarcane juice in the freezer (right) still retains its flavor and vibrant color.
Scientific tests show that simply placing sugarcane juice in the freezer can preserve its color, flavor, and quality for up to 3 months without the need for any additional chemicals or preservatives.
With a freezer temperature lowered to -20 degrees Celsius, sugarcane juice’s shelf life can extend up to 10-12 months without spoilage.
Choosing Safe Sugarcane Juice for Consumption
Sugarcane (Saccharum) belongs to the Poaceae family and is one of the ten most widely cultivated plants in the world. With its low price, easy accessibility, and sweet flavor, sugarcane juice is popular in many countries as a refreshing drink, especially during the summer.
But it doesn’t stop there; sugarcane also contains many polyphenolic compounds, minerals (such as potassium, calcium, sodium, iron, and magnesium), ascorbic acid, and soluble fiber, making it a remedy for various ailments ranging from fever and jaundice to kidney issues.
Research has shown that sugarcane juice can enhance vision, improve cardiovascular and brain health. With its high flavonoid content, it also has the potential to protect cells from degeneration, reducing the risk of cancer and cardiovascular diseases.
However, in many countries, especially in Latin America and Asia, sugarcane juice is often sold by local vendors on the streets, which raises concerns about food safety and hygiene.
Unsafe sugarcane juice can pose risks of bacterial imbalance, stomach pain, and digestive disorders for consumers.
In 2015, Hai Dang Chromatography – one of the 310 laboratories under Eurofins, the world’s leading food quality testing group – randomly sampled sugarcane juice from various shops in Ho Chi Minh City and found that each milliliter contained 210,000 Coliform bacteria, 490,000 aerobic microorganisms, and 18,000 yeast and mold spores.
According to Mr. Huỳnh Ngọc Trưởng, Head of the Microbiology Testing Department at Hai Dang Chromatography, the microbial levels in this sample were 1,000 to 10,000 times higher than the maximum contamination limits set by the Ministry of Health for biological and chemical pollutants in food.
Annual tests of street-sold sugarcane juice conducted by the Ho Chi Minh City Food Safety Department also revealed levels of aerobic microorganisms, Coliform bacteria, and E. coli exceeding permissible limits.
Mr. Trưởng warns that the presence of high levels of microorganisms in sugarcane juice can lead to risks of bacterial imbalance, stomach pain, and digestive issues for consumers. To avoid these problems, it is advisable to purchase sugarcane juice only from reputable establishments.
How to choose a clean street sugarcane juice vendor?
Here are some tips to help you choose a street sugarcane juice vendor that ensures food safety and hygiene, based on the clean practice guidelines from Fraser Health, Canada:
- 1. The area where the sugarcane press is located should be hygienic. Do not leave sugarcane residue in the pressing area as it can ferment and attract flies.
- 2. Use fresh, peeled, and cleaned sugarcane.
- 3. The vendor should wash their hands before and after pressing the sugarcane.
- 4. The sugarcane press and utensils such as collection containers and filters should be cleaned and disinfected every four hours, including at the start and end of the business day.
- 5. Store raw sugarcane and sugarcane juice in the refrigerator. Do not use raw sugarcane or juice that has been left out at room temperature for more than two hours.
With the knowledge mentioned above, we hope you will find a reputable place to buy sugarcane juice that ensures food safety and hygiene.
