• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.687-693
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• 2018

The selective removal and recovery of fermentation inhibitors during purification of sugars from biomass hydrolysates can increase the economic efficiency of the entire process to produce bioalcohol from lignocellulosic biomass. This study investigated the effect of furans in phenols-free biomass hydrolysate on acetic acid extraction in an emulsion liquid membrane system. Under specific operating conditions, more than 99% of acetic acid could be extracted within 5 minutes, and the degrees of extraction of furfural and 5-hydroxymethylfurfural were about 10% and 4%, respectively. The extraction rate of acetic acid was also lower at a higher initial concentration of furfural in the feed phase, which was greater for furfural than 5-hydroxymethylfurfural. Thus, if furfural is first removed from the hydrolysate prior to acetic acid extraction, emulsion liquid membrane would be a more economically efficient way of removing acetic acid.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.9-14
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• 2005

Batch enzymatic hydrolysis of egg yolk protein by protease was carried out at laboratory scale coupled to an ultrafiltration module. Effect of ethanol concentrations on the performance of enzymatic hydrolysis was studied to determine the optimum condition of recovery of hydrolysate. The enzymatic hydrolysis was conducted stepwise with following conditions, $50^{\circ}C$, pH 10.0 and pH 6.5. Ethanol concentration was changed from 10 to $40\%$ (w/w). As ethanol concentration was increased, the recovery yield of total solid and protein in enzymatic hydrolysate was also increased. The content of sialic acid and protein in hydrolysate was independent of ethanol concentration. We also investigated the effect of ethanol concentration on the performance of ultrafiltration. As the concentration of ethanol in yolk protein was increased, the recovery yield of product was increased. Ultra­filtration of egg yolk protein hydrolysate was conducted to increase the content of sialic acid. Four ultrafiltation modules were used in this study, and we evaluated the performance of the UF modules. When Amicon module was used, the recovery percentage of total solid in retentate was $6.0\%$, which is the highest among the modules used. In spite of the difference in the recovery yield of total solid, the purity of sialic acid in retentate was about $2.0\%$, which was 5 times higher than that in feed. It was concluded that the recovery yield and the purity of sialic acid did not correlate with the types of modules and the size of MWCO.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.1033-1043
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• 2020

This study investigated the impacts of gelatin hydrolysate addition on the technological properties and lipid oxidation stability of cooked sausage. Gelatin hydrolysate was prepared from pork and duck skin gelatin, through stepwise hydrolysis using collagenase and pepsin. The cooked sausages were formulated without gelatin (control) or with 1% pork skin gelatin, 1% duck skin gelatin, 1% pork skin gelatin hydrolysate, and 1% duck skin gelatin hydrolysate. The pH, color characteristics, protein solubility, cooking loss, and textural properties of cooked sausages were evaluated, and the 2-thiobarbituric acid reactive substances (TBARS) value was measured weekly to determine lipid oxidation stability during 4 wk of refrigerated storage. Enzymatic hydrolysis of gelatin decreased protein content and CIE L* but increased redness and yellowness (p<0.05). When 1% gelatin or gelatin hydrolysate was incorporated in cooked sausage, however, little to no impacts on pH value, moisture content, protein content, color characteristics, protein solubility, and cooking loss were found (p>0.05). The addition of 1% duck skin gelatin hydrolysate increased the cohesiveness and chewiness of cooked sausages. The inclusion of 1% duck skin gelatin accelerated lipid oxidation of cooked sausages during refrigerated storage (p<0.05), whereas duck skin gelatin hydrolysate caused a lower TBARS value in cooked sausage compared to duck skin gelatin. The results show comparable effects of gelatin and gelatin hydrolysate addition on the technological properties of cooked sausages; however, the oxidative stability of raw materials for gelatin extraction should be evaluated clearly in further studies.

• Nutrition Research and Practice
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• v.3 no.3
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• pp.200-207
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• 2009

This study examined the effects of com gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of camitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.5
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• pp.373-377
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• 1990

Volatile components of whole sardine sauce which was prepared with $7\%$ of complex enzyme-2000($2.18{\cdot}10^4\;U/g solid$), mixed with $6\%$ of invert sugar and heated at $90^{\circ}C$ for 2 hours were compared with those of without invert sugar. Thirty seven kinds were identified from the whole volatile components of hydrolysate heated without invert sugar and fourty three kinds were identified from the hydrolysate heated with $6\%$ of invert sugar. Amines were not detected from the whole volatile components of the chopped whole sardine hydrolysate. Considerable amount of 2,3-dihydrobenzofuran and 2-acetylpyrrole, a little amount of 2,5-hydrofuran, 2-ethylbutanol, 2-pyrone, 2-acetylfuran, 2,6-dimethylpyrazine, 2-acetylpyrazine, 5-methyl-2-furfural, furfuryl acetate, butylpyrrole and 2-methyl-3-hydroxypyrone were detected in the hydrolysate thermally treated with $6\%$ of invert sugar while these were not found in the hydrolysate heated without invert sugar. But the amount of 2-methyt-1-propa-not, hexane, butyl acetate and butyl alcohol were decreased, and acetic acid and butanoic acid were detected as volatile fatty acids.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.192-199
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• 2014

The effects of adding mechanically deboned chicken (MDC) hydrolysates on the quality characteristics of imitation crab stick (ICS) during storage were investigated. ICS was prepared from Alaska Pollack, chicken breast surimi, and protein hydrolysates enzymatically extracted from MDC. ICS samples were divided into 4 groups: without protein hydrolysate (control), added with 0.5% protein hydrolysate (T1), added with 1.0% protein hydrolysate (T2), and added with 1.5% protein hydrolysate (T3). Results showed that crude protein content did not differ significantly among the ICS samples (p>0.05). ICS sample added with MDC hydrolysates had higher crude fat and ash content but lower moisture content than the control (p<0.05). Lightness was significantly lower in T2 and T3 than in the other groups at 0 and 4 wk of storage. Also, whiteness decreased in the groups contained MDC hydrolysates. Breaking force and jelly strength were higher in samples containing MDC hydrolysates compared to control samples (p<0.05). Additionally, saturated fatty acid contents were lower in the groups containing MDC hydrolysates than in control sample groups (p<0.05). Polyunsaturated fatty acid (PUFA) and essential fatty acids (EFA) were significantly higher in T2 and T3 than the control samples. In particular, all samples containing MDC hydrolysates had reduced thiobarbituric acid-reactive substances (TBARS) values at 4 wk. Free radical scavenging activity also was increased with addition of MDC hydrolysates.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.575-581
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• 2010

This investigation was aimed at developing a ready-to-reconstitute beverage by utilizing probiotics and whey protein hydrolysates carrying bioactive peptides. Cheddar cheese whey was ultrafiltered. The 18% protein retentate was subjected to protein hydrolysis using Neutrase. The hydrolyzed retentate was further condensed to 35% total solids and spray-dried at $75^{\circ}C$ outlet air temperature. Different levels of sugar, citric acid and stabilizer were blended for spray-dried hydrolysates. Spray-dried hydrolysate was further inoculated with different levels of probiotics grown in a whey medium and dried in fluidized-bed drier at $40^{\circ}C$ to obtain a ready-to-reconstitute beverage. Hydrolysis was greatest at an enzyme:substrate ratio of 1:25 for 3 h. Spray-dried hydrolysate reconstituted to 1% protein and blended with 15% sugar, 0.2% citric acid and 0.15% xantham gum resulted in a superior product with no sedimentation. Accordingly, sugar, citric acid and xanthum gum were dry-blended with spray-dried hydrolysates. Bifidobacterium bifidum and Lactobacillus acidophilus that was grown separately in a whey medium, blended to produce 2% spray-dried hydrolysate and dried as described above resulted in a readyto-reconstitute beverage mix. The fluidized dried product typically exhibited a probiotic count of $10^8$colony forming units (CFU)/g. However, blending of probiotic to the retentate and direct spray-drying precipitously reduced the probiotic count to $10^4$ CFU/g of powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1759-1766
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• 2013

In this study, the optimal conditions for salmon hydrolysate using squid liver and compositional properties of hydrolysate were investigated. The optimal conditions were $55^{\circ}C$, pH 5.5 and 0.66~0.67% (w/w) in the ratio of squid liver to acidic and thermal treated salmon muscle. The free amino acid of hydrolysate from the acidic treated salmon muscle was higher than that of hydrolysate from the thermal treated salmon muscle, while the total amino acid and mineral were high in the acidic treated salmon muscle. Furthermore, cadmium of hydrolysate from the thermal denatured salmon muscle was below 2 ppm, and has an acceptable level as potential ingredient. The distribution of peptide molecular weight was 40.0% for 1.0~9.5 kDa, 6.7% for 0.5 kDa, and 47.4% of others in hydrolysate from the thermal treated salmon muscle. Both hydrolysates did not show any toxicity against the HepG2 cell line for up to $200{\mu}g/mL$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1677-1685
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• 2012

The autolysate and hydrolysate of a common squid liver, Todarodes pacificus, were prepared. Autolysis (liver ratio, pH, temperature) and Protamex-treated hydrolysis (pH, temperature, ratio of protease to liver) conditions were optimized by response surface methodology using central composite design for under 1 hr of hydrolysis time. The desirability profile indicated that maximum DH could be achieved at a squid liver of 93.5%, pH 6.4, and $47^{\circ}C$ in autolysis, while that of Protamex-treated hydrolysis did at a Protamex-to-squid liver level of 0.33%, pH 6.0, and $55^{\circ}C$. Three amino acids, proline, cysteine, and methionine, were not detected in the total amino acid composition of the Protamex-treated hydrolysate, while they were detected in the free amino acid composition. Cadmium was $8.32{\pm}0.03$ mg/100 g-powder for raw, $3.56{\pm}0.02$ mg/100 g-powder for the autolysate, and $13.26{\pm}0.04$ mg/100 g powder for the Protamex-treated hydrolysate. The major molecular weight ranged from 1.0 to 1.5 kDa for the autolysate and from 210 to 470 Da for the Protamex-treated hydrolysate. Food functionalities of the autolysate, such as surface hydrolphobicity, emulsion activity index, emulsion stability, water, and fat adsorption, were similar to the Protamex-treated hydrolysate. Both the autolysate and Protamex-hydrolysate showed high inhibitory activities on the angiotensin-I converting enzyme. Cell toxicity against the HepG2 cell line was not detected in the autolysate or the Protamex-treated hydrolysate by 200 ${\mu}g/mL$.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.57-62
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• 1976

Using modified technique of Schmidt et al, as described previously (Korean J. Pharmacol 9 : 17, 1973), the stomach of female rats were perfused with physiological saline under urethane anesthesia. The acid-secretory response of the perfused stomach to i.v. hypertonic glucose (50%), casein hydrolysate (20%) or saline (6%) solution were studied with or without histamine or methacholine stimulation. A significant decrease of acid secretion from the rat stomach was induced by i.v. hypertonic glucose or saline solution. The histamine-stimulated acid secretion was also decreased by simultaneous administration of the hypertonic glucose or saline. However, methacholine-stimulated acid response was not affected by the hypertonic glucose. Intravenous infusion of 20% casein hydrolysate solution resulted in an increase in acid output from the stomach under histamine stimuli. These results lead to the conclusion that the inhibitory responses of acid secretion due to i.v. hypertonic glucose solution are brought through the effect of histaminergic, not cholnergic mechanism(s) in the gastric secretion.