Properties of Milk Treated with High-Power Ultrasound and Bactofugation

Abstract

Research background. Two methods of milk treatment were used, ultrasound (innovative method) and bactofugation of milk, after which the physico-chemical and sensory properties of the milk were examined, with the primary aim of achieving consistency of the properties of the milk with pasteurization. Experimental approach. Ultrasound power levels of 200 and 400 W and frequency of 24 kHz with constant cycle were used. Milk treatment duration was 2.5, 5, 7.5 and 10 min with sonification at temperature of 20 °C (room temperature) and thermosonification (ultrasound at temperature higher than room temperature) at temperature of 55 °C. The purpose of this study was to investigate application of high power ultrasound, combined with a slightly increased temperature on: whole cow milk; skimmed cow milk and skimmed cow milk that passed bactofugation process. Results and conclusions. The best sensory grade was achieved when milk was treated with ultrasound power of 200 W, at 20 °C and the processing time was max. 7.5 min. This research shows potential of applications of high-power ultrasound in dairy industry, when combined with bactofugation technology as a pre-treatment for milk and with a slightly increased temperature (up to 55 °C). Novelty and scientific contribution. The application of these two technologies leads to milder processing conditions than pasteurization, an economical and more environmentally friendly technological process preferred by costumers and consumers, but also to a nutritionally beneficial composition of milk.

Microbiological aspects and challenges of whey powders – I thermoduric, thermophilic and spore‐forming bacteria

“…Bactofugation allows for the removal of 98-99% of anaerobic spores, 95% of aerobic spores, and 90-92% of lactobacilli. The sludge that forms after cleaning should be swiftly removed and sterilised, nevertheless (Juraga et al 2021). Bactofugation can be used both before and after the thermal treatment if spore counts are high.…”

“…The sludge that forms after cleaning should be swiftly removed and sterilised, nevertheless (Juraga et al . 2021). Bactofugation can be used both before and after the thermal treatment if spore counts are high.…”

Utilização de ultrassom de alta intensidade em alimentos de origem animal: revisão de literatura

“…Essa tecnologia oferece algumas vantagens em comparação às tecnologias convencionais, como o tempo de processamento, rápida transferência de energia, maior controle de processo, além de ser considerada eco friendly (Chemat et al, 2011). Além disso, o ultrassom auxilia na inativação de microrganismos, na melhoria da textura do produto, na homogeneização e ajuda na incorporação de ingredientes (Awad et al, 2012;Juraga et al, 2021).…”

Effect of Frequency and Duration of Thermosonication on the Physical, Chemical and Microbiological Quality of Cow's Milk

“…The effects on food products are affected by several factors such as temperature, processing time, frequency, ultrasonic power (Carrillo-Lopez et al, 2021;Scudino et al, 2020). Several previous studies proved that thermosonication causes changes in several food product such as, buffalo milk fat globule size decreases at 20 kHz, 25 °C (Abesinghe et al, 2020), denaturation of sweet whey protein at 20 kHz, 65 °C (Barukčić et al, 2015), increase in cow's milk fat content at 24 kHz, 63 °C (Bermúdez-Aguirre et al, 2008), appearance of burnt off-flavors, 2008), the appearance of burnt off-flavor in milk at 24 kHz, 74 °C (Marchesini et al, 2015), no significant change in the pH of cow's milk at 24 kHz, 55 °C (Juraga et al, 2021), reduce total microbes and can maintain the antioxidant activity of galangal rice at 22 kHz, 60 °C (Safitri et al, 2022). Based on this, this study was conducted to determine the effect of frequency and duration of thermosonication with the addition of moderate heating on the physical, chemical and microbiological quality of cow's milk.…”