Immobilization of Microbial Cells in Food Fermentation Processes

Abstract

The purpose of this review is to emphasize existing trends and recent advances in the application of immobilized cell technology so as to implement some innovations in food industry associated with processing, preservation, and storage of the products based on the food safety issues. Attention is focused on the engineering aspects of the immobilized cell techniques with emphasis on the mass-balance-based mathematical modeling of the system. Some aspects of models for safety, quality, and competitiveness of the food processing sector are also presented. Ultimately, development of products with novel properties within the alcoholic beverages, meat processing/ preservation, manufacture of cheese and bread, sweeteners and pigments, as well as nutraceuticals is also addressed. Nomenclature a Specific area of the gel particles (m −1 ) A Area of the particles (m 2 ) Bi Biot number Bi=(K L ×L)/D C Molar concentration (kmolm −3 ) D Diffusivity (m 2 s −1 ) G Mass concentration of immobilized biocatalyst (kgm −3 ) G p Dimensionless inhibition parameter, G p =gh 2 /D s k Rate constant of reaction (kmol −2 m 6 s −1 ) K L Mass-transfer coefficient (ms −1 ) K P Inhibition constant (kmol m 3 ) K S Constant in Monod equation (kmol m 3 ) l Size of gel particle (m) L Dimensionless number, L=l×a R d Ratio of product to substrate diffusivities, R d =D p /D s t Time (s) T Dimensionless time, T=D s t/l 2 V Volume of broth (m 3 ) x Spatial coordinate (m) X Biomass concentration (kgm −3 ) in stationery phaseGreek symbols β Productivity constant (h −1 ) γ Inhibition constant (h −1 ) ηDegree of substrate to product conversion, η= C p∞ (C s∞ +C p∞ ) μSpecific growth rate of bacteria (s −1 ) Ф 2 Thiele modulus, Ф 2 =kl 2 [C p∞ 0 +C s∞ 0 ] 2 /D s Subscripts P Related to the product S Related to the substrate to related to a quantity for the bulk liquid phase max Denotes the maximum specific growth rate Superscript 0 Denotes an initial value

Creation of a new portable biosensor for water toxicity determination

“…Increasing alginate concentration (from 0.5 to 2% (w/v)) decreased their light response. The immobilization of cells in calcium alginate has been widely studied and used in many applications [32][33][34][35][36]. Diffusion of ethanol decreased with increasing alginate concentration [37].…”

Production of Extracellular Isoamylase and Endoglucanase by Entrapped Spores of Rhizopus oryzae PR7

“…These days, in food processing and bio-alcohol producing industries, instead of using whole microbial cells emphasis is being given on the application of immobilized cell technology with special attention to mass-balancebased mathematical modelling of the system [4].The application of immobilized cells for the production of enzymes by microorganisms has been widely studied [5][6][7][8] as it offers various advantages, such as convenience in cell mass separation from the product facilitating continuous operation over a prolonged period lowering the chances of contamination without loss in biomass [9][10][11] and reusability of the cell for at least few consecutive cycles [12]. Moreover immobilization imparts operational stability in enzyme production [13,14].…”

One-step magnetic modification of yeast cells by microwave-synthesized iron oxide microparticles

“…). The advantages of various methods of cell immobilization for bioreactor systems, food technology or environmental applications have been compared in several reviews (Junter and Jouenne ; Kosseva ; Martinez‐Trujillo and Garcia‐Rivero ).…”