Ultrasound-Attenuated Microorganisms Inoculated in Vegetable Beverages: Effect of Strains, Temperature, Ultrasound and Storage Conditions on the Performances of the Treatment.

Daniela Campaniello,Maria Rosaria Corbo,Milena Sinigaglia,Antonio Bevilacqua,Barbara Speranza

doi:10.3390/microorganisms8081219

Abstract

Four microorganisms (Lactobacillus acidophilus LA5, Bifidobacterium animalis subsp. lactis DSM 10140 and Lactiplantibacillus plantarum c16 and c19) were attenuated through ultrasound (US) treatments (40% of power for 2, 4 and 6 min; and 60% for 2 min; pulses were set at 2 s) inoculated in rice–oats–almond–soy-based beverages and stored at 4 °C for eight days. All strains were able to survive throughout the storage independently by the food matrix. Concerning the effect on acidification, the results were analyzed through multifactorial analysis of variance (MANOVA) and the key-findings of this were: (i) The treatment with 40% of power for 6 min was the most efficient at delaying acidification; (ii) Lb. acidophilus LA5 showed the best capacity to delay acidification; (iii) in the soy-based beverage a lower acidification was found. In a second step, L. plantarum c16 and c19 were attenuated, inoculated in rice beverage, stored under a thermal abuse (for 4 and 24 h) and then at 4, 15 and 20 °C. The results showed that only when US were combined with refrigeration temperatures were they efficient at delaying acidification. Thus, a perspective for attenuation could be the optimization of the treatment to design an effective way to counteract acidification also under a thermal abuse.

Highlights

In the past, the function of foods was conceived only in relation to their ability to satisfy humans’ primary need to eat and provide the necessary nutrients
The aim of this study was to evaluate the suitability of US attenuation on four strains in order to counteract the acidification in some vegetable beverages, under both refrigeration and thermal abuse conditions, through two steps: (i) The evaluation of the effect of four different US treatments, for power and exposure time, on the survival of two L. plantarum (c16 and c19), Lb. acidophilus LA5 and Bifidobacterium animalis subsp. lactis 10140) strains inoculated in beverages based on almond, oats, rice and soy, stored for eight days at 4 ◦C, by investigating the effect of US to delay beverage acidification; (ii) the effect of thermal abuse on the performance of attenuation
Samples of rice beverages were separately inoculated to 7 log colony-forming units (CFU)/mL of L. plantarum c16 and c19 attenuated by US treatment (40% of power for 6 min and impulses of 2 s), incubated at 30 ◦C for 4 and 24 h and stored at 4, 15 and 20 ◦C

Summary

Introduction

The function of foods was conceived only in relation to their ability to satisfy humans’ primary need to eat and provide the necessary nutrients. Nowadays, this concept has been extended to physical and mental well-being and functional foods satisfy this new concept. The growing health concerns related to lactose intolerance, allergy to milk proteins, the high cholesterol content as well as the high amounts of saturated fatty acids has directed consumers towards alternative foods to milk and its derivatives. In order to alleviate the drawbacks of dairy based probiotics, the development of non-dairy probiotic products, including food matrices from fruit, vegetables and cereals, has a promising future [3]

Objectives

Methods

Findings

Conclusion