Optimization of air-blast drying process for manufacturing Saccharomyces cerevisiae and non-Saccharomyces yeast as industrial wine starters

Abstract

Wine yeast (Saccharomyces cerevisiae D8) and non-Saccharomyces wine yeasts (Hanseniaspora uvarum S6 and Issatchenkia orientalis KMBL5774) were studied using air-blast drying instead of the conventional drying methods (such as freeze and spray drying). Skim milk—a widely used protective agent—was used and in all strains, the highest viabilities following air-blast drying were obtained using 10% skim milk. Four excipients (wheat flour, nuruk, artichoke powder, and lactomil) were evaluated as protective agents for yeast strains during air-blast drying. Our results showed that 7 g lactomil was the best excipient in terms of drying time, powder form, and the survival rate of the yeast in the final product. Finally, 7 types of sugars were investigated to improve the survival rate of air-blast dried yeast cells: 10% trehalose, 10% sucrose, and 10% glucose had the highest survival rate of 97.54, 92.59, and 79.49% for S. cerevisiae D8, H. uvarum S6, and I. orientalis KMBL5774, respectively. After 3 months of storage, S. cerevisiae D8 and H. uvarum S6 demonstrated good survival rates (making them suitable for use as starters), whereas the survival rate of I. orientalis KMBL5774 decreased considerably compared to the other strains. Air-blast dried S. cerevisiae D8 and H. uvarum S6 showed metabolic activities similar to those of non-dried yeast cells, regardless of the storage period. Air-blast dried I. orientalis KMBL5774 showed a noticeable decrease in its ability to decompose malic acid after 3 months of storage at 4 °C.

Food waste treatment using Bacillus species isolated from food wastes and production of air-dried Bacillus cell starters

“…The collected cells were mixed with 0.5, 1.0, and 1.5 g of the excipients (lactomil and wheat flour, respectively) in the presence of 1 mL of protective agent solution. The mixed bacterial cell pellets were dried in an oven drier (HB-509C, HanBaek, Bucheon, South Korea) at 37C until the moisture content of the dried cells was less than 10% [14]. After air-drying, the samples were analyzed immediately to determine their moisture content and survival rate and then stored at 4°C for later use.…”

“…For the preparation of the air-dried Bacillus cells, including B. licheniformis G1 and B. subtilis E1 cells, commercial skim milk and glucose were selected as protective agents based on the results reported by Lee et al [14]. These authors obtained the highest viability when 10% skim milk was applied to yeast cells.…”

“…There are several methods for preparing microbial starters such as freeze-drying, fluidized bed drying, and spray drying for industrial applications [11][12][13]. Recently, Lee et al [14] developed and optimized a procedure for producing Saccharomyces and non-Saccharomyces yeast starters at the industrial level using an air-blast drying method. Following the protocols of the authors, this research attempted to develop air-dried bacterial cells that could potentially be applied to treat food wastes at the industrial level.…”

Effect of inoculation strategy of non‐Saccharomycesyeasts on fermentation characteristics and volatile higher alcohols and esters in Campbell Early wines

“…The volatile aromatic compounds were determined with a 7890A GC/MS (Agilent Technologies) equipped with a flame ionisation detector (FID) (Lee et al ). The compounds were separated on a DB‐WAX column (60 m × 250 μm × 0.25 mm; Waters).…”

“…Moreover, chaptalisation is necessary for winemaking since the cultivar has low TSS (14–15°Brix), which results in a wine of low flavour (Hwang and Park ). To improve wine quality or to reduce malic acid concentration, several strategies, such as MLF, mixing with different grape cultivars, carbonic maceration and co‐fermentation with non‐ Saccharomyces yeasts, have been attempted (Pozo‐Bayón et al , Yook et al , Chang et al , Sadineni et al , Hong and Park , Hu et al , Lee et al ). Among these approaches, inoculation of grape must with non‐ Saccharomyces yeasts has been widely utilised.…”