• Food Science and Biotechnology
• /
• v.16 no.2
• /
• pp.294-298
• /
• 2007

The actinidin (EC 3.4.22. 14) found in kiwifruit is a cysteine protease. In order to obtain the actinidin gene from the Chinese wild kiwifruit, primers were designed on the basis of the actinidin gene of Actinidia deliciosa, the New Zealand kiwifruit. The 1.2 kb DNA fragment was acquired from the total RNAs of Chinese wild kiwifruit via reverse transcription polymerase chain reaction (RT-PCR), and its DNA sequence was analyzed. Its sequence was determined to share 98.4% homology with the actinidin gene of A. deliciosa. In order to verity the actinidin gene isolated from the Chinese wild kiwifruit in Escherichia coli, the mature gene was amplified via PCR and expressed in E. coli under the control of the T7lac promoter. The actinidin was expressed in E. coli as inclusion bodies, which were solubilized with urea and refolded. The protease activity of the refolded protein was approximately twice as high as that of E. coli BL2l (DE3).

• Korean Journal of Food Science and Technology
• /
• v.25 no.1
• /
• pp.39-45
• /
• 1993

The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

• 한국생물공학회:학술대회논문집
• /
• 2000.04a
• /
• pp.527-530
• /
• 2000

A kiwi fruit ,called as the Chinese gooseberry, is originated from the Yangtze River Valley of Northern China and Zhejiang Province on the cost of Eastern China. Around 1950, a large mass production began at New Zealand with an Improved breeding. Plant origin actinidin from kiwi fruit belongs to the papain family of cysteine proteinase, which in plants includes papain from papaya, bromelain from pineapple, Cl4 protease from tomato and aleurain from barley. Actinidin is involved in the ripening-related gene family. In this study, protease gene of chinese wild kiwi fruit was isolated and characterized. 1.2kb PCR-amplified fragment was obtained from the total RNA using RT-PCR. pWACT-1 was obtained by subcloning of amplified fragment into pGEM-T Easy cloning vector and analyzed nucleotide sequence by DNA sequencing and amino acid sequence. In Result, high levels of homology between wild kiwi and New Zealand cultured-kiwi was obtained.

• The Korean Journal of Food And Nutrition
• /
• v.7 no.2
• /
• pp.87-94
• /
• 1994

A protease, actinidin, was isolated from Cheju kiwi fruit Actinidia chinesis. The enzyme was purified about 8.5 fold with the yield of 25% by column chromatographies of DEAE-Toyopearl and Sphadex. G-100. Purified enzyme gave a single protein band on polyacrylamide gel electrophoresis and its molecular weight estimated by SDS-PAGE was about 27, 000. The optimum pH and temperature were 7.0 and 4$0^{\circ}C$, respectively. This enzyme was stable at the ranges of pH 5.0~9.0 and below 5$0^{\circ}C$. It was also found that Fe+2, Fe+3, and Na+ ions increased enzyme activity, whereas Hg+2 and Co+2 ions decreased. The enzyme was inhibited by phenylmercuric acetate and leupeptin, which indicated that active center of the emzyme had thiol-group. The enzyme reaction followed the Michaelis-Men-ten dkinetics with the Km value of 0.32 mM for casein.

• Fashion & Textile Research Journal
• /
• v.11 no.3
• /
• pp.496-501
• /
• 2009

In this study, a kiwifruit-produced protease was used to improve the quality of the wool and silk fabrics. The wool and silk were treated with the actinidin from kiwifruit. Following this protease treatment, changes in the surface of a single yarn of the fabrics were observed via both an optical microscope and a scanning electron microscope (SEM). In order to determine the amount of dye uptake in the fabric, changes in the K/S value of the wool and silk were measured by spectrophotometric analysis. Also, we performed a tensile strength examination to determine variation in their mechanical properties. By increasing the protease treatment time to 48h, the dyeing properties of fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, because of the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Thereby, we suggest that the kiwifruit-produced actinidin treatment can improve the quality of the fabrics.

• Food Science and Preservation
• /
• v.23 no.3
• /
• pp.291-300
• /
• 2016

Kiwifruit (Actinidia chinensis, Hayward) was stored at $25^{\circ}C$ for 0~30 days and investigated to find out the optimum storage time to obtain the best physical and functional properties for consumers' preference. Kiwifruits was stored at different time period (0, 5, 10, 15, 20, and 30 days) for investigating their physiochemical quality, nutritional components, and functional characteristics. Kiwifruits stored for 20~30 days showed the best physiochemical quality such as higher total acidity and proper firmness. They were also more enriched with dietary fibers, free sugar, and organic acid, although no significant changes were observed in crude protein, crude fat, and moisture content. For functional properties, kiwifruits stored for 20 days showed significantly higher contents of total phenolics, flavonoids, and actinidin. In addition, it showed stronger antioxidant activity, whitening effect, and proteolytic activity when compared with other samples. SDS-PAGE analysis showed the presence of actinidin enzyme in kiwifruits. These results indicated that the kiwifruits stored for 15~20 days possessed excellent quality and high concentrations of nutritional and functional compounds, which could be best for both fresh consumption and product processing.

• Journal of Animal Environmental Science
• /
• v.10 no.2
• /
• pp.119-126
• /
• 2004

The protein in the extracts from the skins of pineapple and kiwi and the optimal conditions to hydrolyze blood, egg and gluten meals with them were investigated. Protein analysis by SDS-polyacylamide gel electrophoresis showed one protein band with 22 kd molecular weight in the pineapple skin extract, and Hve protein bands with 27 kd, 22.5 kd, 22 kd, 19 kd, and 14.4 kd molecular weight in the kiwi skin extract. The 22 kd protein in the pineapple skin extract is assumed to be bromelain, and the 27 kd protein in the kiwi skin extract is assumed to be actinidin, both are pretense. The optimal conditions for hydrolysis of blood, egg, and gluten meals we: 6-24 hours in time, $60^{\circ}C$ in temperature, and pH 4-pH 7.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.4
• /
• pp.641-645
• /
• 2001

To utilize the by-products from whelk processing, whelk internal organ jeotgal was manufactured by adding pineapple and kiwifruit juices containing bromelain and actinidin, respectively. The protease activities of pineapple and kiwifruit juices were 52 and 248 unit/mL, respectively. 1 kg ground whelk internal organ was immersed to 12.5% salt concentration and then the 20, 50, or 100 mL of fruit juice were added in it. the quality of products fermented for up to 70 day at 1$0^{\circ}C$ was observed. Jeotgal wit pineapple juice showed lower pH and higher amino nitrogen content than with kiwifruit juice on 70 day of fermentation. the total nitrogen contents was the highest on 30 day of fermentation and stable thereafter. Although total numbers of microorganism were increased as fermentation progressed, there were no correlations among the juices or its adding amounts. It was thought that interactions between kinds of natural microflora and the proteases from fruit juices, and other constituents in jeotgal affected total nitrogen content of jeotgal and the growth rate of natural microorganisms. Of the all jeotgals in this study, no coliform was found It is suggested that the preparation of jeotgal with pineapple or kiwifruit juice is effective aspect of safety and quality.

• Journal of Life Science
• /
• v.12 no.6
• /
• pp.752-758
• /
• 2002

This study was investigated on properties and thermostability of gelatin-degrading proteinases in the fruit of Actinidia chinensis (kiwifruit) for the industrial application. Three gelatin-degrading proteinases (PI, PII and PIII) were detected from the pulp of fruits. The molecular weights of these proteinases, PI, PII and PIII, were approximately 220 kD, 51 kD, and 26 kD respectively, on the basis of gelatin-containing SDS-PACE. The optimum pH of these proteinases ranged from 2.0 to 5.0 with a maximal activity at pH 4.0. These proteinases had a high sensitivity to E-64 and iodoacetate which are cysteine protease inhibitors, and required DTT, cysteine, and $\beta$-mercaptoethanol for their activities which are stimulators for cysteine proteases. These results indicate that these proteinases are cysteine proteinases and the proteinase PIII is actinidin (EC 3.4.22.14), based on the molecular weight and/or susceptibility against proteinase inhibitors. These proteinases were strongly activated by $Ca^{2+}$, $Mg^{2+}$ and $Mn^{2+}$, whereas strongly inhibited by Zn$^{2＋}$ and Hg$^{2＋}$. However, these proteinases have slightly different susceptibility against other cations ($Ca^{2+}$, $Cu^{2+}$, $Al^{3+}$, $Ca^{3+}$. The temperature stability of proteinase PIII was more stable than proteinases PI and PII. Moreover, proteinase PIII remained stable below $50^{\circ}C$ for 48hr, showing the residual activity above 75% of the enzyme activity.

• Journal of Animal Science and Technology
• /
• v.65 no.1
• /
• pp.32-56
• /
• 2023

This review explores the factors that improve meat protein digestibility and applies the findings to the development of home meal replacements with improved protein digestion rates in older adults. Various methods improve the digestion rate of proteins, such as heat, ultrasound, high pressure, or pulse electric field. In addition, probiotics aid in protein digestion by improving the function of digestive organs and secreting enzymes. Plant-derived proteases, such as papain, bromelain, ficin, actinidin, or zingibain, can also improve the protein digestion rate; however, the digestion rate is dependent on the plant enzyme used and protein characteristics. Sous vide processing improves the rate and extent of protein digestibility, but the protein digestion rate decreases with increasing temperature and heating time. Ultrasound, high pressure, or pulsed electric field treatments degrade the protein structure and increase the proteolytic enzyme contact area to improve the protein digestion rate.