Like in many applications, solutions of high sugar content can cause serious problems due to microorganism contaminations. Hence, the main aim of this work was to study a nanofiltration process for GOS purification at 5 °C and 60 °C that may circumvent or reduce potential microbial growth. Process performances and rejection behaviors of monosaccharide as well as individual GOS components were compared. Operating at 5 °C is more advantageous especially with respect to the oligosaccharide (OS) recovery yield. Using a NF membrane (NP030) at 45 bar, a product purity of 85% (based on monosaccharide content) and an OS recovery yield of 82% could be achieved. However, a low average permeate flux of 3 L/m 2 h had to be accepted. A diafiltration step improved product purity to 90% with 30% losses of OS. A qualitative theoretical discussion shows that a possible change of the pore radius distribution depending on temperature could play a role in solute rejection as well as selectivity.

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Summary The objectives of this study were to evaluate the feasibility of producing goat milk containing galactooligosaccharides (GOS) by β‐galactosidase and to determine the sensory attribute and stability of goat milk containing GOS. The results indicated that the maximum GOS obtained were approximately 13.9% of total sugars at pH 4.5 and temperature 40 °C. The sensory attribute of the obtained GOS was determined using a 5‐point hedonic scale in terms of taste, flavour, appearance and overall acceptability. There were significant increases in taste and overall acceptability of goat milk containing higher GOS concentration when compared to regular goat milk (control). Also, goat milk containing GOS presented a good stability over the acidic conditions. GOS in goat milk were also stable after the high heat treatment and shelf life conditions.

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The solid-state fermentation (SSF) of soybean meal (SBM) by Bacillus velezensis K1 to improve protein quality and reduce allergenic proteins as well as raffinose family oligosaccharides was investigated in this research paper. The fermentation parameters affected protein hydrolysis, namely soybean meal moisture, size of inoculums, time and temperature of fermentation were evaluated in the soybean meal. The best solid-state fermentation conditions with the highest degree of hydrolysis (16.65 ± 4.08%) were 50% (w/w) moisture content, 10% (v/w) inoculum size, 40°C and 72 hours fermentation. Under these optimal conditions, large proteins in the soybean meal were hydrolysed. Proteins with molecular weight <10 kDa increased significantly from 34.05 to 48.22% (P<0.05). Additionally, allergens (glycinin and β-conglycinin) and raffinose family oligosaccharides decreased. The bands representing glycinin and β-conglycinin on SDS-PAGE were considerably reduced and their degradations were 96.47% and 49.60%, respectively. The raffinose family oligosaccharides, primarily stachyose and raffinose also decreased by 73.57% and 22.76%, respectively. With the capability of producing protease and other carbohydrate hydrolytic enzymes (cellulase, pectinase, amylase and invertase), B. velezensis K1 presents great potential for increasing the nutritional quality of the soybean meal as an ingredient in the feed industry.