Assessment of the biological activity of kefir grains by biospeckle laser technique

Abstract

This work presents the biospeckle laser technique as a potential tool to analyse the kefir grains activity. In the present work, the kefir grains biological activity was measured from quantitative measurements by means of their speckle activity. The aim was to show that the biospeckle laser is a potential methodology to assess kefir grains viability, monitoring the kefir grains during the beverage production. The monitoring of the activity of the kefir is a key factor to guarantee the efficiency of the production of beverages, however the routine ways it is done compromise its use in the online production. The kefir grains were illuminated by a laser HeNe 17 mW 632 nm and analysed by the numerical biospeckle laser method. The results presented the statistical separation of the kefir in distinct levels of activity as expected. This can be an innovative technique to be used in the beverage industries for kefir grains inoculum control.

Laser biosensor use for the microbial metabolic activity assessment of kefir vinegar

“…The sensitivity of the laser biospeckle technique was observed in the following of a growth curve with the defined phases Lag (adaptation) and Log (exponential growth, stationary growth and death) ( Figures 2 A and 2 B). These results were similar to the those obtained by Guedes et al (2014), whose aim was to show that the biospeckle laser is a potential methodology to assess the biological activity of kefir grains, monitoring them during the production of milk beverage. Zdunek & Herppich (2012) used biospeckle to monitor the chlorophyll biological activity in apples, to evaluate the potential relationships between the biospeckle activity and chlorophyll content in apples.…”

“…An optical technique with potential use in biological metrology, particularly in biological activity, is the dynamic laser biosensor or biospeckle, associated to biological material (Braga Jr et al, 2003;Guedes et al, 2014). When a laser beam is scattered by a biological sample, the scattered waves generated in the illuminated sample create the speckle pattern that changes its image in accordance with the changes in the monitored material.…”

“…Interference patterns formed on them were captured by a CCD camera of 640 × 486 pixels (Systems Ltd, Chennai, India), with a 1/60 s shutter speed, at 0.08 s rate, creating a collection of 128 images. The analysis of the images, from the laser illumination, was performed according to Guedes et al (2014). Image analyses from the laser illumination were performed by monitoring the temporal history of the speckle pattern (THSP) and its numerical output, the values of the differences (AVD) (Guedes et al, 2014):…”

“…The analysis of the images, from the laser illumination, was performed according to Guedes et al (2014). Image analyses from the laser illumination were performed by monitoring the temporal history of the speckle pattern (THSP) and its numerical output, the values of the differences (AVD) (Guedes et al, 2014):…”

Ciência e Tecnologia dos Alimentos–Volume 4

“…Kefir is a culture employed to produce beverages, such as the traditional Russian beverage also named "kefir" which is from milk, and has low alcohol contente (Simova et An optical technique with potential use in biological metrology, particularly in biological activity, is the dynamic Laser Speckle, or Biospeckle biosensor, when associated to biological material (Braga et al, 2003;Guedes et al, 2014;Catalano et al, 2019). When a laser beam is scattered by a biological sample, the scattered waves generated in the illuminated sample create the speckle pattern that changes its image in accordance with the changes in the monitored material.…”