Process For Preparing Nutritious Silkworm Pupa For Human Food

Process for preparing nutritious silkworm pupae for human food.
Field of Invention
This invention relates to a process for preparing nutritious silkworm pupae for human food.
Background of Invention
Silkworm Pupae contain balanced nutrition for human diet and therefore gaining roaring popularity among Koreans, Chinese, Japanese and Assam, Meghalalya, Nagaland of India as a delicious food item. It contains a balanced amount of moisture, chitin, water soluble proteins, carbohydrates, amino acids and vitamin C besides crude protein as the major constituent. The essential amino acid content of the pupal protein was similar to that of whole egg protein with the exception of tryptophan (0.9 g/16 g of N). For the production of pupae as nutritious food for human consumption either special rearing can be adopted or large quantity of pupae waste that accumulates in silk reeling process in India could be utilized within 7 days of marketing in a better manner so that the cost of production of silk can be reduced. Annual production of spent pupae in India is 1,08,224 MT, so if organized properly, huge quantity of raw material will be available. There are so many recipes for food purpose available as a brief out line from different international patents. In this direction. Central Sericultural Research and Training Institute, Mysore venturing out a novel preparation of pupae as a food from Indian hybrids PM x CSR2 and CSR2 x CSR4, which can be preserved for three months as such and will be most nutritious and liking dish for human consumption.
Silkworm pupae is being used in China, Korea and Japan as traditional protein rich food. There are 18 Chinese patents regarding different delicious Chinese dishes preparations using silkworm pupae as one of the ingredient. Two patents (YANG ZHANG, 1994 Patent no. CN1093536 and SUN XIAO, 2005, patent no. CN1635102) found in similar type of present work, whereas, in depth they are totally different in collection, overall processing, preservation and packaging of finished material from present work.
Preparation of different dishes of Pupae for human food
QINGPING MENG and HAIRONG XIE (1991 patent no. CN 1052420) discloses the method for producing foodstuffs containing nutritive components in silkworm chrysalis. This method includes following technological steps: crushing selected silkworm pupa, diluting with water, filter for obtaining thick milk of silkworm pupa, addition of starch, egg and flavouring, and steaming in a steamer or baking in an oven. It features simple technology and easy manufacture and can be used to make different foodstuffs such as cake, can, sausage and slice of silkworm pupa. YUPING ZHANG and ZIKE TENG (1993 patent no. CN1071554) explained edible silkworm chrysalis preparing and flesh-preserving method. The preparation method includes 1) purifying and peeling off, 2) flavouring the purified silkworm chrysalis, 3) coating paste, 4) passing the pasted

chrysalis through boiling oil, 5) steaming and roasting and finally packaging. Advantages of this technology is simple processing method, original nutriment and taste of the silkworm chrysalis are preserved, it changes the seasonal food of silkworm chrysalis into perennial one. YANG ZHANG (1994 Patent no. CNl093536) prepared silkworm chrysalis canned food. The invented main point is that the fresh silkworm chrysalises are sterilized, and then the assistant materials are added, and then boiled in water, and further are canned, so that the invented product can be made up. Said invention has the characteristics of easy to storage and convenient for eating. WEIQIANG CHEN and SUQING ZHI (1995 patent no. CN1113421 produced food from silkworm chrysalis. The silkworm chrysalis food is made of silkworm chrysalis, hot pepper powder, ginger powder, sugar, edible salt and soy sauce and has the functions of nourishing brain, benefiting intelligence and supplementing protein. HETING ZHOU (1996 CNl 123112) discloses the method for making shortbread of silkworm chrysalis. Manually peeled fresh silkworm chrysalises are washed, then dewatered in dewatering machine, fried in edible oil and put into dewatering machine to remove residual oil, and finally added with seasoning. Advantage is that whole shape of silkworm chrysalis, crisp taste and without uncomfortable smell. XU PAN AO (1999) in CN1235789 explained the process of shelled silkworm chrysalis. Silkworm chrysalis is first frozen fully and then soaked in hot water at 30-60° for 30-70 sec to thaw the shell fully. After that, the shell is cut at the thickest part and eliminated. Shelled silkworm chrysalis is finally cooked, and thus cooked shelled silkworm chrysalis has no itchy feeling. The present invention is especially suitable for food processing factory, restaurant, household and other places. CHEN SHUNZHI (2000 in patent no. CNl259317) discloses processing method of silkworm chrysalis used for snack food, silkworm chrysalis and tussah chrysalis is used as raw material which are partially or completely dehulled, cut apart and mixed with vegetable or animal protein, mould pressed to form and packed in flexible package. ZHANG XIN AN 2000 (patent no. CNl267484) explained silkworm chrysalis food making process through the processes of defatting and eliminating fishy smell with alcohol, microwave roasting, twice coating, far infrared roasting, coloring, cooling and packing. It is easy to eat, and suitable for all people and has the original nutritious components maintained. Similarly ZHAO SHULIN et ai, (2000) in their patent no. CNl260130 revealed the treatment method for silkworm chrysalis used as food. The detoxification treatment method of silkworm cocoon as raw material of food uses lipolytic polar organic solvent as extracting solvent, and adopts heating and refluxing extraction method to implement treatment. It can remove the contained hormones compound, rancidified fatty acid and other hazardous material, and can improve its taste, so that the silkworm cocoon treated by said invention not only can be eaten directly, but also can be used as additive for supplementing protein nutrient in various foods. HAN DINGXIAN et al, (2003 patent no. CN1460435) prepared liver-protecting functional food made up by using ligustrum fruit and silkworm chrysalis. They uses the oleanolic acid extracted from ligustrum fruit and zymolyzed dried powder made up by using silkworm chrysalis as main raw material, and adds the auxiliary materials of excipient and vitamins and utilizes a certain preparation process to obtain the invented liver-protecting functional food. Silkworm chrysalis cooking method was disclosed by ZHOU XIAOMING (2004 in CNl509653). It includes such steps as carefully choosing cocoon chrysalides, removing impurities, sterilizing, baking for dewatering, adding flavouring in

oil, heating oil to a certain temp, frying the chrysalides in the oil until they are semi-cooked, cooling for 3-5 min, frying them in boiling oil until they are nearly cooked, cooling for 2 min, and frying in boiling oil. Its advantages are crisp skin, soft inside and long storage time. HUANG SHOUPENG et al., (2004, patent no.CN1554281) prepared silkworm pupa thick chilli sauce and the nutritive value of silkworm pupa was maintained. The silkworm pupa thick chilli sauce is produced with silkworm pupa, black sesame, walnut kernel and chopped chilli, and the production process includes the following steps: sorting, washing and boiling silkworm pupa in salt water for 3-5 min; making black sesame powder; crushing walnut kernel into grains; mixing boiled silkworm pupa, black sesame powder, walnut kernel grains and chopped chilli; vacuum packing and sterilization. The present invention is a kind of health food. ZHANG JIN and ZHU CHANGZHONG (2005, patent no. CN1568821) prepared natural fresh-kept soft-skin silkworm chrysalis instant food, which consists of material choosing, quick freezing, unfreezing, curing, preheating, drying and disintegrating, dressing and packaging. ZHOU DONGFENG (2005, patent no CN1644107) invented the process of vacuum plastic sealing pack and production of a silkworm flavored pupae food with rich nutrients through choosing silkworm pupa by two steps, shearing open for flavouring, drying in air, frying in hot oil, vacuum packing and microwave sterilizing. SUN XIAO (2005, patent no. CN1635102) discloses method for making silkworm chrysalis nourishing vinegar by using silkworm chrysalis as the main raw material, the preparing process comprises the steps of silkworm chrysalis degreasing, proceeding deodorization treatment, drying, disintegrating, boiling and cooling down, fermenting with alcohol and acetic acid, employing circulated drenching method to obtain the end product, which contains 18 amino acids needed by human body. TANG YIQUN (2005, patent no. CN2737145Y) prepared edible silkworm chrysalis food. He filed another patent in 2006 (no. CN 1778205) explored an instant silkworm pupa food which is composed of a silkworm pupa meat and a shell for covering said silkworm pupa meat. Its preparing process includes such steps as cleaning each silkworm pupa, heating, separating peel from the main body of silkworm pupa, drying in the air, freezing, peeling, antistaling treatment and packaging. FAN TAO WU (2006, patent no. CN1843174) prepared fresh silkworm chrysalis noodle and discloses the process for preparation, wherein the raw material constituents include flour, table salt, calcium stearate, and live silkworm chrysalis slurry. The preparing process comprises the steps of mixing dough, curing, tabletting, slitting, cutting and packaging.
It is a well-known fact that presently pupae which are obtained after reeling of silkworm cocoons are generally thrown away though they are very rich in protein, oil, carbohydrate and minerals. If these pupae hygienically preserved, sealed packed and transported to those places of India and other countries, where, it can be sold and consumed delightfully by human being. By-products of an industry are often brought to purposeftil utilization to augment the profits. All the patented recipes revealed that pupae preserved by complicated process and canned or fried in oil or boiled and peeled off or microwave oven processed or mixed with other ingredient and prepared nutritious food. To suite Indian conditions, an alternative method for silkworm pupae preparation has been standardized. The present invention is especially suitable for using pupae in food processing factory, restaurant, household and other places. These pupae can be consumed as such or fiirther used for preparing different dishes.

Object of invention
The main object of this invention is to develop a process for preparing nutritious silkworm pupae for human food.
Other object is to develop a process wherein silkworm pupae can be used as protein rich delicious non-vegetarian dish.
Another object is to avoid the problem of pollution from reeling waste pupae.
Yet another object is to reduce the cost of silk upto some extent.
Statement of Invention
This invention relates to a process for preparing nutritious silkworm pupae for human
food comprising. Collection of wet pupae at correct age, after spinning 4th -8th day, most
preferably 6th day wherein case of fresh pupae can directly be used for processing and
pupae from reeling unit, purchasing and stifling of cocoons should be preferably from 4th'
-8th day, most preferably 6th day. Cleaning of pupae by washing with clean water, drying
and degreasing, by drying clean pupae, defatted with organic solvent by hot percolation
for 3-12 hr preferably 4-5hr, followed by airdrying to remove organic solvent. Sterilizing
and cooking of pupae by autoclaving for 10-40 min preferably 20-30 min. cooling further
room temperature preferably to 25±1°C.
Deodorization and preservation is done initially in alcohol 30-90%, preferably in 50-60% and vinegar with known proportion for 24-72 hrs. Sterilization of pupae alongwith pressured solution airtight, sealed, packed.
Brief description of accompanying drawings
Figl. shows fresh and dry pupae of silkworm. Fig 2. shows preserved nutritious silkworm pupae.

Detailed description of Invention
♦ Collection of pupae at correct age: After spinning 4th - 8th day, most preferably 6 day is the correct day for collecting the pupae. In case of fresh pupae directly can be used for processing, whereas, pupae from reeling unit, purchasing and stifling of the cocoons should be preferable from 4th - 8th day, most preferably 6th day. Reeling of cocoons should be co-coordinated within next 5-10 days most probably within 7 days. Wet pupae can be collected.
♦ Cleaning of Pupae: Collected pupae are washed with clean water and good pupae are sorted-out mechanically.
♦ Drying and degreasing: This step is optional. For defatted pupae preparation collected cleaned pupae were dried and defatted with organic solvent by hot percolation for 3-12h preferably 4-5h, then air dried to remove organic solvent.
♦ Sterilizing and cooking of pupae: All pupae autoclaved for 10- 40 min
preferably 20-30 min to sterilized and cooking.
♦ Cooling: autoclaved pupae further cooled to room temperature preferably to 25±1 C.
♦ De-odorization and Preservation: Pupae are preserved initially in alcohol can be 30 to 90% preferably in 50- 60% and vinegar with known proportion for 24-72 hrs. Consequent three changes of solvent have been given and finally pupae preserved for three - four months without affecting any nutrition value.
♦ Following correct procedure the pupae tissues are preserved and original colour of pupae remain unchanged for 3-4 months.
♦ Packing: Pupae along with preserved solution can be sterilized, air tight, sealed packed and ready for transportation.
♦ Defatted mass pupae contains N2, crude protein, digestible protein, soluble protein and carbohydrate in the range of 9.18, 57.4, 48.35, 29.0 and 15.80 g/100 g respectively, whereas pupae with fat contains 7.72, 48.3, 40.09, 16.40 and 10.20 g/100 g respectively.

♦ Defatted pupae contains significantly more N2 15.90 %, crude protein 15.85%, digestible protein 17.08%, soluble protein 43.44% and carbohydrate 35.44% as compared to pupae with fat. Defatted pupae further tested for its ash and crude fibre content and found that 7.1 % of ash and 0.76% of crude fibre were present.
Results are presented in Annexure I

We Claim
1. A process for preparing nutritious silkworm pupae for human food comprising.
a) Collection of wet pupae at correct age, after spinning 4th -8th day, most preferably 6th day wherein case of fresh pupae can directly be used for processing and pupae from reeling unit, purchasing and stifling of cocoons should be preferably from 4th -8th day, most preferably 6* day.
b) cleaning of pupae by washing collected pupae with clean water.
c) drying and degreasing, by drying clean pupae, defatted with organic solvent by hot percolation for 3-12 hr preferably 4-5hr, followed by airdrying to remove organic solvent.
d) Sterilizing and cooking of pupae by autoclaving for 10-40 min preferably 20-30 min.
e) cooling further room temperature preferably to 25± 1 °C.
f) deodorization and preservation is done initially in alcohol 30-90%, preferably in 50-60% and vinegar with known proportion for 24-72 hrs.
g) sterilization of pupae alongwith pressured solution airtight, sealed, packed.

2. A process for preparing nutrition silkworm pupae for human food as claimed in claim 1, wherein in collection of pupae reeling of cocoons is co-ordinate within next 5-10 days, most preferably within 7 days.
3. A process for preparing nutrition silkworm pupae for human food as claimed in claim 1, wherein in deodorization and preservation stage, consequent three changes of solvent have been given so that finally pupae are preserved for three to four months without affecting any nutrition value.
4. A process for preparing nutrition silkworm pupae for human food as claimed in claim 1, wherein Defatted mass contains N2, crude protein, digestible protein, soluble protein and carbohydrate in the range of 9.18, 57.4, 48.35, 29.0, 15.80 g/100 respectively whereas pupae with fat contains 7.72, 48.3, 40.09, 16.40 10.20 g/100 respectively.

5. A process for preparing nutrition silkworm pupae for human food as claimed in
claim 1, wherein the Defatted pupae contains more N215.90%, crude protein
15.85%, digestible protein 17.08%, soluble protein 43.44% and carbohydrate
35.44% as compared to pupae with fat.
6. A process for preparing nutrition silkworm pupae for human food as claimed in
claim 1, wherein Defatted pupae contains 7.1% of ash and 0.76% of crude fibre.
7. A process for preparing nutrition silkworm pupae for human food as claimed in
claim 1, wherein drying and degreasing step is optional.