Postharvest commercial processing technology of strawberry

Strawberries are not only visually appealing with their vibrant red color, but also offer a perfect balance of sweetness and tartness. They are packed with essential nutrients and are considered a rare combination of color, aroma, and flavor in the world of fruits. Often referred to as the "Queen of Fruits," strawberries are highly valued both domestically and internationally. However, due to their delicate nature, they are extremely susceptible to damage and microbial contamination during harvesting and transportation, which can lead to spoilage and a significant loss in commercial value. In recent years, the production of strawberries has increased rapidly, yet challenges in storage and preservation have limited their marketability to local areas. The short shelf life and concentrated harvest time result in a large number of spoiled berries, causing serious waste of resources and economic losses. Additionally, the environmental impact of such waste has discouraged many strawberry growers. Therefore, it is crucial to develop effective post-harvest processing techniques that ensure the quality and longevity of strawberries. **Preparation Before Storage** 1. **Variety Selection**: Different strawberry varieties exhibit varying levels of resistance to storage and fungal diseases like gray mold. Some varieties that are more suitable for long-term storage and transport include Jixin, Shitou, Gorera, Baozao Zaosheng, Green Seeds, Brandon Baoshuo, and others. 2. **Harvesting**: Strawberries should be harvested when about three-quarters of the fruit surface turns red. It's best to pick them on a sunny day, after the morning dew has dried, or in the early evening before temperatures drop. Avoid harvesting at noon when the temperature is high. Hand-picking is recommended, and care must be taken to avoid touching the fruit directly with fingers. Remove any diseased or damaged fruits and place the healthy ones gently into special fruit trays. The ideal size for these trays is 90 cm x 60 cm x 15 cm. Once filled, the trays can be placed into polyethylene bags, sealed, and quickly sent to cold storage. If special trays are unavailable, small baskets with a height of around 10 cm can be used instead, but care must be taken to avoid turning or bruising the fruit. 3. **Sorting**: After harvesting, remove all rotten, diseased, or misshapen fruits. Select only those that are uniformly colored, well-shaped, and intact. 4. **Cleaning**: Use a specialized strawberry washing machine, then rinse the fruits in a 0.05% potassium permanganate solution for 30–60 seconds, followed by a thorough rinse with clean water and drainage. 5. **Pre-cooling**: Pre-cooling should be done as soon as possible after harvest to reduce the time between picking, grading, and packaging. After harvest, strawberries should be placed in cold storage immediately. Special containers used for harvesting should be arranged in rows, with at least 15 cm of space between each column. Avoid placing the containers in areas where cold air from the storage unit directly hits the fruit, as this could cause freezing. Maintain humidity above 90% and keep the temperature around 5°C (not below 3°C). During April and May, when temperatures rise, the relative humidity should be kept at 7–8°C, and if needed, the temperature can be adjusted slightly to prevent condensation inside the boxes. Try not to open the storage door for at least two hours after placing the fruit inside. For example, if the fruit temperature reaches 15°C, it should be pre-cooled for over two hours to bring it down to 5°C. If the temperature is 20°C, pre-cooling should last 2–4 hours. **Storage and Preservation Techniques** 1. **Refrigeration**: The ideal storage temperature for strawberries is 0°C with a relative humidity of 90–95%. After harvest, the fruit should be transported to cold storage and pre-cooled to 1°C. 2. **Wax Coating**: A modern technique involves using chitosan-based coatings, which help maintain the firmness and vitamin content of strawberries for up to 31 days. The optimal concentration of chitosan is currently recommended at 0.5%, while a composite coating of 0.8% ethylparaben and 0.5% stearate monoglyceride can also be effective. 3. **Calcium Treatment**: Applying calcium solutions helps reduce the loss of soluble solids, hardness, vitamin C, and acidity during storage. It also inhibits microbial growth, reduces decay, and extends the shelf life of strawberries. 4. **Modified Atmosphere Storage**: Store strawberries at 0–0.5°C with 85–95% humidity, 3% oxygen, and 6% carbon dioxide. When packing, ensure there is more than 10 cm of space between each carton. 5. **Chemical Preservation**: - Soaking strawberries in a solution of 0.1–0.15% phytic acid, 0.05–0.1% sorbic acid, and 0.1% peracetic acid can extend their shelf life to 1 week at room temperature or 15 days under refrigeration, with a good fruit rate of 90–95%. - Sulfur dioxide treatment involves placing strawberries in plastic containers along with 1–2 bags of slow-release sulfur dioxide agents, keeping them at a distance from the fruit and sealing the container. This method can preserve strawberries for up to 20 days, achieving a good fruit rate of 66.7% and a product rate of 61.1%. **Transportation** The best way to transport strawberries is via refrigerated trucks. It’s advisable to load and unload during cooler times, such as early morning or late evening. Use small, well-ventilated packaging, and consider placing the fruit in plastic bags with 10% carbon dioxide. Handle the fruit carefully to avoid collisions and compression. Ensure that the transportation tools are clean and equipped with sun protection, insulation, and rain coverage to maintain quality throughout the journey.

Roughness Profilometer

Roughness Profile Measuring Instruments all-in-one machine is an all-in-one machine for measuring profile shape and surface roughness, which has the powerful function of analyzing and measuring profile shape and surface roughness. Realize accurate measurement of dimensions, shape and roughness. It is mainly used to measure the parameters of the surface micro-geometry and macro-geometry of mechanical parts such as straightness, inclination, angle treatment, roundness treatment, double-groove treatment, double-arc treatment, etc.

Performance characteristics
1. High accuracy, high stability and high repeatability: meet the measurement accuracy requirements of the measured part.
1) Select high-precision grating measurement system and high-precision inductance measurement system, with high measurement accuracy;
2) Independently researched and developed high-precision grinding guide rail system, which has good wear resistance of guide rail materials and ensures stable and reliable operation of the system;
3) High-performance linear motor drive system ensures high measurement stability and good repeatability.
2. Intelligent management and detection software system:
The operation interface of the instrument is friendly, the operator can easily master the operation of the instrument, and the use is very simple.
1) The company has accumulated many years of practical measurement software design experience to provide customers with simple, practical and fast operation experience;
2) The company has invested many years of human resources in the development of instrument software, with special software copyright;
3) With powerful functions, it can automatically process data, print reports in various formats, and automatically display, print, save and query measurement records;
The data can be archived or printed in a centralized manner, which does not take up the verification operation time;
4) The measurement range is wide, which can meet almost all types of workpiece profile measurement, including special measurement functions of special workpiece screw, bearing, thread and other profiles;
5) The measured section can be selected automatically and manually for evaluation, and software functions can be customized according to customer requirements;
6) Powerful CNC automatic measurement and automatic labeling analysis function;
For large quantities of the same type of workpiece, it can carry out CNC measurement, automatically analyze and process the data, and carry out SPC statistics on the data, and can carry out statistical analysis in various ways to give quality control guidance;
7) It can automatically record and save all verification results by using computer large-capacity database storage.
3. It can also measure surface roughness and contour shape
With the same main body, you can only switch different modules to measure the profile shape and microroughness of the product.
4. Multi-parameter evaluation
The roughness can be automatically evaluated according to different standards, including Ra, Rp, Rv, Rz, Rt, Rmax, Rq, Rsk, Rku, RSm, RPc, Rdq, Rdc, Rmr and P parameters, W parameters, Motif parameters, Rcore parameters and other multi-parameter evaluation.
5. Thickness parameter measurement
When measuring the roughness parameters, the height and thickness of some film steps within 600 microns can be measured simultaneously. The measurement is convenient, and the accuracy is controlled within 2% H (H, the total height of measurement). It is especially suitable for high-precision measurement occasions without scratches.
6. Measuring force system:
With the voice coil motor force measuring system, the force measurement can be continuously adjustable from 10 to 150 mN, and the force measurement resolution can reach 0.2 mN; It avoids the force measurement error caused by the vibration of the surrounding environment when the old weight is loaded, and reduces the measurement error caused by the change of the force measurement.
7. Intelligent protection system:
The instrument is protected by hardware and software in all directions, which can effectively protect the instrument host and probe, and reduce the probe and instrument damage caused by personnel's operation errors.
8. Flexible manual control:
The instrument is equipped with a special separating operating rod, which can be placed at any position to control the operation when the instrument is operated and moved, and the measuring needle can be roughly positioned before measuring the workpiece; In the case of leaving the computer, the operating rod has the functions of moving the measuring needle left and right/up and down, emergency stop, the angle swing of the measuring rod up and down, and multi-level speed adjustment.

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Zhejiang dexun instrument technology co., ltd , https://www.dexunmeasuring.com