Skin Gelatin Hydrolysates Research Articles

Antimicrobial and antioxidant properties of chitosan-furcellaran-gelatin hydrolysate coatings enhanced with bioactive peptides

The aim of the study was to investigate the antioxidant and antimicrobial properties of novel, edible biopolymer coatings consisting of chitosan, furcellaran, carp skin gelatin hydrolysate and 8 different bioactive peptides: Lfcin-β, MBP-1, PLGG, LL37, Cys-LL37, melittin, RW4 and nisin. In vitro analyses consisted of evaluating FRAP and ABTS radical scavenging properties as well as effectiveness against various food pathogens. Consequently, the coatings were used to investigate their antimicrobial effect during cold storage of smoked pork ham dipped into the coating solutions with and without the presence of CaCl2. Finally, the 2 most effective coatings were applied onto fresh cold stored pork loins with different doses of the investigated peptides (1.25–10 μg/mL). The biopolymer matrix had high radical scavenging properties (76.94%) and FRAP value (5.41 μmol of Trolox/mL), however, the antioxidant power was reduced when peptides were included. The coatings with peptides inhibited the growth of all tested food pathogens aside from Aspergillus flavus. They successfully inhibited the growth of total viable counts (TVC) with reductions even above 3.5 log cfu/g. The inclusion of CaCl2 provided contradictory results for different groups and it was impossible to confirm its effectiveness. Coatings with RW4 and LL37 were selected as the most promising and proved effective in inhibiting the TVC of fresh pork loin, even at doses of 1.25–2.5 μg/mL. The newly developed coatings exhibit high antioxidant and antimicrobial power and could be used to effectively extend the shelf-life of perishable meat products.

Characterization and evaluation of antioxidant properties of skipjack (Katsuwonus pelamis) tuna skin gelatin Hydrolysate

The present society is extremely conscious of the lifestyle-related ailments and the serious consequences that result from an unhealthy diet and lifestyle. A holistic approach to incorporating nutraceuticals into one's lifestyle has become the current trend. Protein hydrolysates with antioxidant potential have gained critical commercial importance. Protein hydrolysates are produced from food industrial remnants in order to reduce production costs and achieve sustainable resource management. The food industry generates a greater proportion of waste from fisheries, and with the consistent requisite for fish-based products, utilisation of remnants remains a critical concern. Fish hydrolysates have been discovered to have exceptional physical, chemical, and functional properties. It is noteworthy that fish hydrolysates have strong antioxidant properties against reactive oxygen species. In the current research, gelatin prepared from the processing waste of skipjack tuna (Katsuwonus pelamis) skin were hydrolysed by proteolytic enzyme papain. The obtained gelatin hydrolysate showed ~33% degree of hydrolysis (DH). The surface-active properties of Skipjack tuna skin gelatin hydrolysate (SSGH) revealed pronounced foaming and emulsion properties at low protein concentrations. SSGH demonstrated higher antioxidant efficacy by in vitro antioxidant assays. In conclusion, the resulting hydrolysates demonstrated remarkable antioxidant potential, as well as great development prospects for a variety of applications. Further studies with regard to isolation, purification and identification of and peptide sequences improve the quality of functional foods.

Antioxidant Activity of Gelatin Hydrolysate from Nile Tilapia (Oreochromis niloticus) Skin by Hydrolysis Using Flavorzyme

Nile tilapia skin is one of the wastes produced by the tilapia fillet industry that contains quite high protein. One form of Nile tilapia skin utilization that is very potential is gelatin, which is known to have bioactive potential when hydrolyzed properly. The choice of Flavorzyme as a hydrolyzing agent is because it can hydrolyze proteins specifically and does not cause damage. The result of gelatin hydrolysis by flavorzyme at 50°C was the gelatin hydrolysate liquid product. The purposes of this research were to determine the effect of different concentrations of Flavorzyme on the antioxidant activity of Nile tilapia skin gelatin hydrolysate and the best enzyme concentration on Nile tilapia skin gelatin hydrolysate. This research method used a completely randomized design with different enzyme concentrations (0%, 0.5%, 1% and 1.5%). The data obtained were tested by normality test, homogeneity test, ANOVA test, and followed by the honest significant different test to find out the real difference in treatment. The results of data analysis showed that the addition of different concentrations of the flavorzyme had a significantly different effect (P<5%) on the degree of hydrolysis, protein content, and DPPH value. The best Nile tilapia skin gelatin hydrolysate was the product with addition of 1% flavorzyme enzyme concentration with a hydrolysis degree value of 51.52±3.66%, protein content of 8.46±0.24%, and an antioxidant activity value of 31.97. ±1.88%.

Effect of Adding Bovine Skin Gelatin Hydrolysates on Antioxidant Properties, Texture, and Color in Chicken Meat Processing

(1) Background: Phosphates are used in the food industry to improve water retention and product quality. However, when consumed in excess, they can be harmful to health. Instead, bovine skin gelatin hydrolysates present health benefits such as being a rejuvenating agent, stimulating collagen production, and improving food quality, in addition to being a source of protein. The effect of the addition of bovine skin gelatin hydrolysates on the texture and color of thermally processed chicken meat (boiled type) and antioxidant activity was evaluated. (2) Methods: Hydrolysates were prepared with subtilisin with the degree of hydrolysis being 6.57 and 13.14%, which were obtained from our previous study. (3) Results: The hydrolysates improved the firmness of the meat matrix compared to the control. Additionally, the hydrolysate with a 13.14% degree of hydrolysis reached the same firmness (p > 0.05) as the commercial ingredient sodium tripolyphosphate at its maximum limit allowed in the food industry when it was applied at 5% (w/w meat) in the meat matrix, improving firmness over the control by 63%. Furthermore, both hydrolysates reached a similar color difference to sodium tripolyphosphate at its maximum allowed limit when applied at a concentration of 2% (w/w meat). Additionally, it was found that these hydrolysates obtained the same antioxidant activity as sodium tripolyphosphate, capturing free radicals at 10%. (4) Conclusion: The findings of this study suggest that bovine skin gelatin hydrolysates can be applied as an ingredient with functional properties, being an alternative to phosphates to improve the quality of meat products.

Phosphorylation modification of tilapia skin gelatin hydrolysate and identification and characterization of calcium-binding peptides

In present study, complex protease was utilized to prepare tilapia skin gelatin hydrolysate (TSGH), and the phosphorylation conditions of TSGH were optimized using calcium-binding capacity. The phosphorylation degree of TSGH under the optimal conditions was 0.55%. The calcium-binding capacities of TSGH and phosphorylated TSGH were 44.21 and 62.87 µg/mg, respectively. Phosphorylation remarkably improved the calcium-binding capacity of TSGH. Forty-four peptides and 14 phosphopeptides were identified in phosphorylated TSGH, and SGPAGPK and its phosphopeptide, (p)SGPAGPK, were screened. The calcium chelates of SGPAGPK and (p)SGPAGPK were examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and mass spectrometry (MS). Phosphorylation of SGPAGPK effectively increased its calcium-binding capacity. SEM results indicated that SGPAGPK-Ca and (p)SGPAGPK-Ca were formed as new compounds. FTIR and MS results indicated that the carboxyl and phosphate groups of Ser and the amino group of Lys may be the calcium chelation sites.

Anti‐hypercholesteraemic and antioxidative activities of camel skin gelatin hydrolysate: effect of enzyme type, enzyme: substrate ratio and time of hydrolysis

SummaryCamel skin gelatin hydrolysate (CSGH) was prepared using different proteolytic enzymes [alcalase (A), protease (P) and their combination (AP (1:1))], hydrolysis time (2, 4 and 6 h) and enzyme: substrate (E/S) ratio (1%, 3% and 5%). In general, the degree of hydrolysis (DH) increased with increasing hydrolysis time for all enzyme treatments. CSGHs generated with alcalase showed significantly higher lipase (LP) inhibitory activity compared with protease‐derived CSGH at all hydrolysis conditions (P &lt; 0.05). Whereas higher cholesterol esterase (CE) inhibitory activity was observed with CSGH produced by protease (P &lt; 0.05). However, when CSGHs were produced using AP, the highest LP and CE inhibitory activity were recorded at 3 and 1% E/S ratio during 2 and 4 h of hydrolysis, respectively (P &lt; 0.05). Antioxidant assays revealed that CSGHs showed improved radical scavenging activities compared with native CSG (P &lt; 0.05). Overall results indicated that CSGHs with higher in vitro anti‐hypercholesteraemic and antioxidant activities could be obtained by enzymatic hydrolysis.

Identification, Screening, and Comprehensive Evaluation of Novel DPP-IV Inhibitory Peptides from the Tilapia Skin Gelatin Hydrolysate Produced Using Ginger Protease.

Inhibition of dipeptidyl peptidase-IV (DPP-IV) is an effective therapy for treating type II diabetes (T2D) that has been widely applied in clinical practice. We aimed to evaluate the DPP-IV inhibitory properties of ginger protease hydrolysate (GPH) and propose a comprehensive approach to screen and evaluate DPP-IV inhibitors. We evaluated the in vitro inhibitory properties of fish skin gelatin hydrolysates produced by five proteases, namely, neutral protease, alkaline protease, bromelain, papain, and ginger protease, toward DPP-IV. We screened the most potent DPP-IV inhibitory peptide (DIP) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with in silico analysis. Next, surface plasmon resonance (SPR) technology was innovatively introduced to explore the interactions between DPP-IV and DIP, as well as the IC50. Furthermore, we performed oral administration of DIP in rats to study its in vivo absorption. GPH displayed the highest degree of hydrolysis (20.37%) and DPP-IV inhibitory activity (65.18%). A total of 292 peptides from the GPH were identified using LC-MS/MS combined with de novo sequencing. Gly-Pro-Hyp-Gly-Pro-Pro-Gly-Pro-Gly-Pro (GPXGPPGPGP) was identified as the most potent DPP-IV inhibitory peptide after in silico screening (Peptide Ranker and molecular docking). Then, the in vitro study revealed that GPXGPPGPGP had a high inhibitory effect on DPP-IV (IC50: 1012.3 ± 23.3 μM) and exhibited fast kinetics with rapid binding and dissociation with DPP-IV. In vivo analysis indicated that GPXGPPGPGP was not absorbed intact but partially, in the form of dipeptides and tripeptides. Overall, the results suggested that GPH would be a natural functional food for treating T2D and provided new ideas for searching and evaluating potential antidiabetic compounds. The obtained GPXGPPGPGP can be structurally optimized for in-depth evaluation in animal and cellular experiments.

Influence of storage conditions on functional properties of multilayer biopolymer films based on chitosan and furcellaran enriched with carp protein hydrolysate

In this paper, the impact of water activity regarding storage environment on mechanical and water properties is presented, as well as the structural and morphological features of triple-layered films. Furcellaran (FUR), chitosan (CHIT) and carp skin gelatin hydrolysates (HGEL) were used for the production of the film. The films were made using a casting method, in which three successive stages were applied. First stage: preparation (pouring onto the mould) of 1st layer – FUR + HGEL, second: 2nd layer preparation (pouring onto 1st layer) – FUR, and third: 3rd layer (pouring onto 1st layer) – CHIT + HGEL. The second and third steps began after gelation of the previously poured layer. The drying process of the film was carried out for 24 h under a fume hood at room temperature. The mechanical properties of control sample was: tensile strength The control sample has tensile strength 7.76 ± 0.35 MPa, elongation at break – 3.69 ± 0.33%, maximum breaking load – 15.86 ± 0.58 N. Water properties of control sample – water absorption a solubility were 25.80 ± 1.14% and 52.91 ± 1.31%, respectively. Reducing the water content in the film increased its tensile strength (from 7.76 ± 0.35 MPa for the control film to 14.36 ± 0.07 MPa) and elongation at break (from 3.69 ± 0.34% for the control film to 8.74 ± 0.69%). Reducing water content in the film also decreased its ability to absorb water, which is crucial in the case of biodegradable films due to their hydrophilic nature. The multimolecular sorption of the films was described using the BET model. Structural and morphological changes observed on the basis of surface and cross-section photographs of the films confirm the negative impact of high water activity on the film and its mechanical parameters.

Evaluating the Properties of Ginger Protease-Degraded Collagen Hydrolysate and Identifying the Cleavage Site of Ginger Protease by Using an Integrated Strategy and LC-MS Technology.

(1) Methods: An integrated strategy, including in vitro study (degree of hydrolysis (DH) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) and in vivo study (absorption after oral administration in rats), was developed to evaluate the properties of the fish skin gelatin hydrolysates prepared using different proteases (pepsin, alkaline protease, bromelain, and ginger protease). Meanwhile, in order to identify the hydrolysis site of ginger protease, the peptides in the ginger protease-degraded collagen hydrolysate (GDCH) were comprehensively characterized by liquid chromatography/tandem mass spectrometry (LC-MS) method. (2) Results: The GDCH exhibited the highest DH (20.37%) and DPPH radical scavenging activity (77.73%), and in vivo experiments showed that the GDCH was more efficiently absorbed by the gastrointestinal tract. Further oral administration experiments revealed that GDCH was not entirely degraded to free amino acids and can be partially absorbed as dipeptides and tripeptides in intact forms, including Pro-Hyp, Gly-Pro-Hyp, and X-Hyp-Gly tripeptides. LC-MS results determined the unique substrate specificity of ginger protease recognizing Pro and Hyp at the P2 position based on the amino acids at the P2 position from the three types of tripeptides (Gly-Pro-Y, X-Hyp-Gly, and Z-Pro-Gly) and 136 identified peptides (>4 amino acids). Interestingly, it suggested that ginger protease can also recognize Ala in the P2 position. (3) Conclusions: This study comprehensively evaluated the properties of GDCH by combining in vitro and in vivo strategies, and is the first to identify the cleavage site of ginger protease by LC-MS technique. It provides support for the follow-up study on the commercial applications of ginger protease and bioactivities of the hydrolysate produced by ginger protease.

Exploring structural features of potent dipeptidyl peptidase IV (DPP-IV) inhibitory peptides derived from tilapia (Oreochromis niloticus) skin gelatin by an integrated approach of multivariate analysis and Gly-Pro-based peptide library

There are abundant dipeptidyl-peptidase IV (DPP-IV) inhibitory peptide motifs in collagen sequences due to high content of Pro. However, the structural features of the most potent DPP-IV inhibitory peptides were not fully elucidated. In this study, peptides from tilapia skin gelatin hydrolysates with different DPP-IV inhibitory activities were analyzed by UPLC-MS/MS and multivariate analysis, and a Gly-Pro-type peptide library was constructed to elucidate their structural features. Results showed that peptide length had a dominant effect on the DPP-IV inhibition of collagen-derived peptides. Moreover, Gly-Pro-type peptides (e.g., GPA- and GPI- types) containing 4 ∼ 9 residues showed a potent DPP-IV inhibition, the IC50 values of which were 2.15 ∼ 10.43 times lower than that of Gly-Pro-Xaa tripeptides. More importantly, different proteases had discrepancy in releasing these peptides, among which papain could release them to a greater extent due to its strong preference for Arg in the S1 subsite and Pro in the S3 subsite.

Protective effects of tilapia (Oreochromis niloticus) skin gelatin hydrolysates on osteoporosis rats induced by retinoic acid

Tilapia skin gelatin hydrolysates (TSGH) were obtained by complex protease hydrolysis. The amino acid sequences of 50 peptides in TSGH were identified, and most of these peptides were found to contain the -Gly-Pro-sequence. The osteoporosis (OP) rat model induced by retinoic acid was prepared, and the effects of different doses of TSGH on OP in vivo were evaluated. Serum calcium (Ca) and phosphate (P), alkaline phosphatase activity, and osteocalcin levels in OP rats were regulated by TSGH. The bone length, dry weight index, maximum load, and Ca content of OP rats significantly increased by treatment TSGH in a dose-dependent manner. Micro-CT images of the femurs and tibias of the rats indicated that the bone mineral density, cortical bone thickness, and cortical/trabecular bone area ratios were recovered and that OP symptoms were improved. Tartrate-resistant acid phosphate and hematoxylin-eosin staining showed that osteoclast numbers and histomorphological changes in the femurs in OP rats could be recovered by TSGH.

Separation and identification of collagen peptides derived from enzymatic hydrolysate of Salmo salar skin and their anti-inflammatory activity in lipopolysaccharide (LPS)-induced RAW264.7 inflammatory model.

Inflammation is considered as a major risk for the pathogenesis of chronic diseases. Due to the adverse events caused by the long-term use of anti-inflammatory drugs, it is necessary to develop alternative and safe dietary supplements from natural products against inflammation. In this study, flavourzyme hydrolysate (for 0.5hr) presented the strongest anti-inflammatory activity, which was further separated by ultrafiltration and column chromatography, followed by LC-MS/MS identification. Peptide APD, QA, KA, and WG were identified as anti-inflammatory peptides, which significantly reduced secretion of NO, IL-6, IL-1β, and TNF-α in inflammatory macrophages. Among them, peptide QA showed the best overall anti-inflammatory effect, with the IC50 value against NO production of 849.3μM. Most of the identified anti-inflammatory peptides were stably against digestion, and they had abundant frequencies in the α (I/II) chain of Salmo salar collagen. Our findings indicated the potential of S. salar skin hydrolysates as functional food to prevent inflammation. PRACTICAL APPLICATIONS: Long-term use of anti-inflammatory drugs causes adverse events like gastrorrhagia, and it is necessary to develop alternative and safe dietary supplements from natural products against inflammation. Salmo salar skin, as a major byproduct of total fish, has not been effectively utilized during processing. In this study, novel anti-inflammatory oligopeptides with high activities were separated and identified from S. salar skin gelatin hydrolysate, which were stably against digestion, and presented a high bioavailability and abundant frequencies in collagen. Our study highlighted the added value of aquatic by-products and suggested that S. salar skin collagen hydrolysate could be used as a promising dietary supplement against inflammatory diseases.

Protein hydrolysates from boarfish (Capros aper) and Atlantic salmon (Salmo salar) skin gelatin improve metabolic control in genetically obese diabetic (ob/ob) mice

There is increasing interest in dietary protein for management of Type 2 diabetes mellitus (T2DM) and obesity. The effects of twice-daily oral administration of a salmon skin gelatin hydrolysate (SSGH, 50 mg/kg), boarfish protein hydrolysate (BPH, (50 mg/kg), metformin (200 mg/kg), or saline control, were investigated in ob/ob mice. Non-fasting blood glucose was significantly reduced with SSGH (p&lt;0.01), BPH (p&lt;0.001) and metformin (p&lt;0.001), which were reflected in reductions in glycated haemoglobin (HbA1c) (p&lt;0.001, p&lt;0.01 and p&lt;0.01, respectively). Responses to oral and intraperitoneal glucose tolerance were improved (p&lt;0.05-0.01), as well as circulating plasma lipid profiles (p&lt;0.05-0.001). Chronic BPH treatment increased circulating plasma insulin (p&lt;0.01), whereas SSGH improved insulin sensitivity (p&lt;0.05), versus respective controls. All treatments significantly reduced energy intake (p&lt;0.05-&lt;0.001) versus (ob/ob) controls, without affecting overall bodyweight. These findings suggest that fish hydrolysates mediate potent anti-diabetic actions similar to metformin and might be suitable for the management and prevention of T2DM.

Structure-function relationship of fermented skate skin gelatin-derived bioactive peptides: a peptidomics approach.

The online version contains supplementary material available at 10.1007/s10068-021-00998-6.

Water-holding capacity of enzymatic protein hydrolysates: A study on the synergistic effects of peptide fractions

The synergistic effects of peptides in bovine skin gelatin hydrolysate (BSGH) on the water-holding capacity (WHC), measured as cooking loss, were studied. These peptides were isolated from the hydrolysate in fractions with different hydrophobicities by reversed-phase chromatography on C18 separation columns. Each peptide fraction was included in the meat matrix at various concentrations for the study of water retention. The fraction with the highest WHC (F5) was obtained. The experimental design consisted of a central compound design with axial points; the independent variables were X1 (ingredient concentration in the meat sample) and X2 (concentration of fraction F5 in the ingredient). The dependent variable was cooking loss. The WHC studies showed substantial synergistic effects occurred between the fractions within the BSGH, and the peptide fractions reduced the cooking loss by 62.96% with respect to a sample without the ingredient. However, a decrease of 42.26% was observed for the F5 fraction. This fraction corresponds to the highest WHC applied for the concentration of 3 g/100 g. The results suggest a synergistic WHC effect of the peptides present in the BSGH since this effect was significantly reduced (p ≤ 0.05) when the peptide fractions were separated.

Bioactive properties of marine fish skin gelatin hydrolysate: Optimisation using response surface methodology

Adverse effects of free radicals on food oxidation have increasingly been investigated recently. Antioxidants have many health benefits as bioactive materials and are widely used in food industries. The effects of three main factors namely, time (60, 150, 240 min), temperature (40, 52, 65℃) and enzyme to substrate ratio (1, 3, 5%) on fish gelatin hydrolysation were studied in order to obtain optimum antioxidative properties. Response surface methodology (RSM) was used to fit the model and ridge analysis to optimise the selected factors. The percentage of Fe2+ chelating activity was considered as the response. R2 confirmed that the model fitted well with the experimental data (R2 = 0.97). Optimal conditions were found to be at a temperature of 56.55°C, enzyme to substrate ratio of 4.93% and time of 149.23 min. Under optimum conditions, metal chelating activity achieved was 82.33%. The results showed that fish skin gelatin hydrolysate had good antioxidative properties and could be a candidate for in vivo studies for industrial applications. Keywords: Antioxidant, Fish gelatin hydrolysate, Metal chelating activity, Response surface methodology

Protease Hydrolysates Ameliorates Inflammation and Intestinal Flora Imbalance in DSS-Induced Colitis Mice

Wheat germ and fish skin usually has not been completely utilized and sometimes may be discarded, thus causing a lot of waste. Here, we aim at exploring the therapeutic anti-inflammatory effects of protease hydrolysates of wheat germ and fish skin on the ulcerative colitis (UC) mice. In the current study, wheat germ protein hydrolysates (WGPH) and fish skin gelatin hydrolysates (FSGH) treated mice had a longer colon than the DSS-induced mice. Moreover, protease hydrolysates reversed DSS-induced gut dysbiosis. Protease hydrolysates were likely to shift the balance of the intestinal flora on inflammation. In summary, these findings suggested that protease hydrolysates might serve as a latent therapy for UC treatment.

Protocol for Designing New Functional Food with the Addition of Food Industry By-Products, Using Design Thinking Techniques-A Case Study of a Snack with Antioxidant Properties for Physically Active People.

The aim of the work was to develop an easy-to-follow protocol for designing novel functional products with the addition of food industry by-products using design thinking techniques. As a result, a 12-step protocol has been designed and presented. The protocol consists of steps from the initial formation of the design team, through all the stages of the production and prototyping, until establishing the final storage conditions and creating final documentation. The protocol has been validated and explained using a case study in which a fish industry by-product hydrolysate with bioactive properties was used to develop a novel functional food product for physically active people: a date bar with carp meat and carp skin gelatin hydrolysate. Following the 12 steps presented in the protocol resulted in developing a food product with high nutritional value and antioxidant power which remains stable during storage at reduced temperatures. Moreover, the product is characterized by good sensory qualities and can be easily implemented into full-scale production. The newly designed protocol is an easy-to-follow method that could be used in almost any kind of food industry sector to sucesfully develop user-focused functional food products with by-product addition.

One- and double-layered furcellaran/carp skin gelatin hydrolysate film system with antioxidant peptide as an innovative packaging for perishable foods products

In this study, two active packaging types were produced: single-layer biopolymer films with a polysaccharide – furcellaran and carp skin gelatin hydrolysate; two-layer films with identical composition, but synthetic peptide Alanina-Tyrosine addition. The procedure objective was multiplying antioxidant effects of the hydrolysate complexed with furcellaran. Films were used on Atlantic mackerel (storage 4 °C, 15 days); samples were analysed for changes in microbiological quality, TVB-N, biogenic amine content, fatty acid composition, TBARS. Consumer analysis was performed characterising mackerel carcass perception depending on implemented active coatings. The developed innovative single- and double-layer coatings effectively slow down lipid oxidation processes, especially at the initial period of Atlantic mackerel storage in refrigerated conditions. The coatings effectively inhibited microorganism growth, extending shelf-life by 2 days, single-layer coatings showing greater efficiency. According to consumers, coating application did not adversely affect product attractiveness parameters. The developed innovative coatings show great applicative potential as a new active packaging for perishable foods.

Effects of Gelatin Hydrolysates Addition on Technological Properties and Lipid Oxidation of Cooked Sausage.

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.