Lyophilized Probiotic Lactic Acid Bacteria Viability in Potato Chips and Its Impact on Oil Oxidation

Abstract

To produce a new probiotic-containing food product, potato chips, as the most preferred fast food, were chosen. Preferably, it should be preserved for a long period without oxidation. The presented study aimed to compare potato chips containing two lyophilized probiotic lactic acid bacteria (Bifidobacterium longum ATCC 15708 and Lactobacillus helveticus LH-B02) in order to retard lipid oxidation. Lyophilization of probiotics was carried out into two cryoprotective media—skim milk (SM) and gelatin/glycerol (GG) as lactose-free medium. Results revealed that GG and SM media were the most suitable for lyophilization of B. longum and L. helveticus, respectively. The lyophilized live cells were incorporated in potato chips, packed and their effect on oil oxidation was assessed. Results showed that the lyophilized B. longum in SM remained alive at 6.5 log CFU/g for 4 months at 30 °C. Interestingly, potato chip bags containing B. longum lyophilized in SM medium exhibited a decrease in peroxide value (PV) and acid value (AV) of the extracted oil by 40.13% and 25%, respectively, compared to the control bags. The created probiotic potato chips containing B. longum fulfill the criteria of the probiotic product besides the prime quality and sensory attributes.

Application of Tarkhineh Fermented Product to Produce Potato Chips With Strong Probiotic Properties, High Shelf-Life, and Desirable Sensory Characteristics

“…This decreasing trend was probably due to the temperature shock in the first twenty days and the subsequent adaptation process in the remaining days of storage. The same results were observed by Mostafa (2020) where the cell viability of lyophilized Bifidobacterium longum and Lactobacillus helveticus in potato chips after two months of storage dropped from 10.14 to 0.00 log CFU g −1 and 9.90 to 0.00 log CFUg −1 respectively (Mostafa, 2020).…”

“…The probiotic carriers such as potato chips are usually stored at room temperature (25 • C) or refrigerator (4 • C) for at least 4 months. Hence, stability tests were performed under the mentioned conditions (Colakoglu and Gursoy, 2011;Mostafa, 2020). The probiotic cells in potato chips were counted every 20 days for up to 120 days at 25 • C and 4 • C.…”

“…Then, for more crispness, they were soaked in CaCl 2 solution (1%) for 15 min. After the refined soybean oil reached a temperature of 200 °C in a stainless steel pan, the potato slices were fried for 5-7 minutes and cooled after taking the extra oil ( Mostafa, 2020 ).…”

“…The Tarkhineh paste containing probiotics was transferred through a sterile tank by a pump to the sprayer head at the end of the machine to turn into fine liquid droplets. Under the laminar flow cabinet, the droplets were sprayed on the surface of the potato chips and then dried (Mostafa, 2020). The size of probiotic drops was measured using a laser diffraction particle size analyzer (Mastersizer 3,000, Malvern Instruments, United Kingdom).…”

“…Lyophilization is the most common method to preserve probiotics in pharmaceutical and food products. However, the high sensitivity of probiotics to cell water loss during the process and the inefficiency of the method during long storage periods are the chief drawbacks of lyophilization ( Mostafa, 2020 ).…”