Effects of microwave on extracellular vesicles and microRNA in milk

Area of Science:

• Biochemistry
• Molecular Biology
• Food Science

Background:

• MicroRNAs (miRNAs) are small non-coding RNA molecules with regulatory functions.
• Extracellular vesicles (EVs) in milk are implicated in intercellular communication and can carry biomolecules like miRNAs.
• The impact of common food processing techniques, such as microwave irradiation, on milk's miRNA and EV content is not fully understood.

Purpose of the Study:

• To investigate the effects of microwave irradiation on the microRNA (miRNA) content of milk.
• To assess the impact of microwave treatment on milk extracellular vesicles (EVs).
• To determine if EVs play a protective role in maintaining miRNA stability in milk.

Main Methods:

• Milk samples were subjected to microwave treatment.
• MicroRNA (miRNA) concentration was quantified using real-time PCR.
• Total RNA content was measured using a spectrophotometer.
• Extracellular vesicle (EV) microstructure and size distribution were analyzed by scanning electron microscopy and dynamic light scattering.
• Acridine orange staining was used to assess RNA content within EVs.

Main Results:

• Microwave treatment significantly reduced miRNA expression and total RNA content in milk compared to untreated samples.
• Scanning electron microscopy and dynamic light scattering revealed damage to milk extracellular vesicles (EVs) after microwave treatment.
• Two distinct populations of EVs with average sizes of 147.50 nm and 22.14 nm were identified.
• Acridine orange staining indicated lower total RNA content in microwaved milk EVs.

Conclusions:

• Microwave irradiation negatively affects the miRNA content of milk.
• Damage to milk extracellular vesicles (EVs) by microwave treatment likely contributes to miRNA loss.
• Milk extracellular vesicles (EVs) appear to play a crucial role in protecting and stabilizing miRNAs within milk.