Measuring pH in Fruits and Vegetables with Sensor Probe.

Fruit and vegetable consumption is an important factor that promotes growth. Furthermore, age-related development reduces the risk of chronic noncommunicable diseases such as cardiovascular disease, high blood pressure, diabetes, and dementia. aging disease The destruction of cellular tissues in the body is caused by the degeneration of various organs, including cancer, which is caused by various free radicals. As a result, eating fruits and vegetables, which are high in antioxidants, will help us avoid disease, and eating vegetables and fruit at their perfect time is also important. Because freshness indicates the greatest nutritional value. Vegetables and fruit can be preserved in a variety of ways. canning, pickling, or freezing Everything is dependent on the pH, which ensures a long shelf life. as well as product freshness.


Most fruits are acidic at low to medium pH levels because they are high in organic acids such as citric acid, lactic acid, and malic acid, resulting in natural fruit acids. In addition to the typical organic acids derived from fruit flavors. According to scientific evidence, natural organic acids like lactic acid and acetic acid It inhibits the growth of microorganisms that cause spoilage. according to the Food Organization’s legal requirements The pH ranges for LACF (Low Acid Canned Foods) based fruits have been established by the United States Food and Drug Administration (USFDA) :


Range of pH


3.30 – 4.30


4.50 – 5.29

6.13 – 6.58


4.80 – 6.80


3.69 – 4.34


5.20 – 6.00


3.20 – 4.00


5.18 – 5.60


One of the five food groups is vegetables. It is a low-energy source of food. and is an important source of vitamins and minerals that are required by the body Other nutrients with health benefits include dietary fiber, antioxidants, and so on. The majority of vegetables are flavorless. from the practice of eating nutritious foods It is recommended that you consume 4-6 cups of vegetables per day, or 4-6 ladles, to help you gain energy. and complete nutrients based on the body’s requirements The pH ranges for LACF-based vegetables are defined based on standard requirements as follows :


Range of pH


5.20 – 5.93


5.40 – 5.90

4.90 – 5.50

Onion, Shallot

5.30 – 5.80


5.60 – 5.90


5.88 – 6.40


5.20 – 6.80


4.30 – 4.90


6.00 – 7.50

The importance of pH measurement in fruits and vegetables

Fruit acidification is related to pH and results in a decrease in pH, so pH monitoring is required. Determining the pH value of fruits and vegetables is critical for proper pH control. for the preparation of fruits or other products such as jellies or jams, etc. There are numerous canning techniques, which are used to preserve vegetables and various seasonal fruits based on pH.

Pickling is another method of preserving vegetables. And, because a high acidity level inhibits microbial growth, acidic fruits with pH levels lower than 4.6 are mostly preserved by adding vinegar or salt. Furthermore, the pickling product’s pH may change due to processing and packing techniques. As a result, it should be closely monitored.

Fruit and vegetable MAP packaging is a food preservation technique used to extend the shelf life of fresh or processed foods. To maintain the product’s good taste, texture, and appearance, the airtightness of the packaging is reduced by lowering the temperature and oxygen levels. A decrease in pH in MAP-rich fruits and vegetables indicates lactic acid bacterial growth, according to a scientific article. This degrades the overall quality and freshness of fruits and vegetables, and thus pH measurements can help us study the impact of this preservation technique on shelf life.

Challenges and Challenges of pH Measurement in Fruits and Vegetables

Fruits and vegetables are solid by nature. This makes it difficult for the electrolyte to enter the sample pH directly. Furthermore, the interaction between the sample and the electrolyte is restricted to pH sensors that use traditional ceramic junctions. The fact that the joints are easily clogged has a direct impact on the efficiency and accuracy of pH readings in fruits and vegetables. The problem is summarized in the table below. and the potential effects on pH measurement when measuring fruit and vegetable samples with conventional sensors



Solid sample

Due to the standard probe geometry, penetration through the sample is difficult. The delicate membrane can be damaged. causing an error reading.

Sample preparation

It takes a long time to mix the samples together.

Cleaning the sensor after measurement

The sensor is dirty from accumulating on the sensitive membrane. difficult to clean And the solid part from the sample can easily clog the ceramic body.

Vegetable and fruit fibers will accumulate on the probe’s glass membrane. It prevents the membrane’s response to transmit signals. The efficiency of measurement will be low. and repeated measurements may cause the probe’s membrane to become dirty because of the accumulation of various contaminants that are difficult to remove This accumulation slows the measurement response by interfering with the interaction of the electrolyte and the membrane with the sample. It also keeps the electrolyte from mixing with the sample, which could lead to measurement errors. Many reactions occur in the body, such as assisting in the maintenance of acid-base balance and electrolyte balance. Maintain the chemical balance between the blood and the tissues. Some minerals help muscle cells and the nervous system function normally. It is also necessary for the enzyme system to function properly during the metabolic process. or the body’s metabolic system.

The pH Meter is a highly precise and accurate instrument.
pH meters come in a variety of styles, including pen, hand-held, tabletop, and wall-mounted models. The use of a pH meter to measure pH is best suited for industrial applications. If the appropriate measuring tool is chosen for the application.

pH Meter from Hanna


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