• 제목/요약/키워드: traditional Korean soup

검색결과 127건 처리시간 0.028초

다문화 음식 급식에 대한 하남지역 중학생의 인식, 만족도, 메뉴 기호도 및 영양사의 태도연구 (Student, Dietitian Reactions to Multicultural Food Service in Hannam School District)

  • 김희섭;임재롱
    • 한국식생활문화학회지
    • /
    • 제26권5호
    • /
    • pp.478-489
    • /
    • 2011
  • Student and dietitian reactions to a multicultural food service menu were studied. Food habits in a multicultural family could delay the acculturation of the children to traditional Korean food and could cause the isolation of children from the community. Also, Korean students need to be exposed to other cultures and foods because it can be a challenge to eat novel foods when students grow up. To help both multicultural and Korean children adjust to new foods, a multicultural menu was included in a school's food service. Students regarded the multicultural menu as access to another culture, but they felt that improvement of the food quality and menu diversity were required. The degree of satisfaction with the food quality, appearance, freshness, temperature, and menu diversity were all moderate. The multicultural menu was served as a single menu item or a combination menu item. The main dish single items - pasta, jajangmyeon, onigiri, hamburgers, rice and curry, kaupatmu, kaupatkung, and donburi - were liked, but nasi goreng was liked only moderately. The soup - based dish single item, tempura soba, was liked, while tomyum was disliked. The side dish single items - tangsuyook, Japanese donkatsu, baked sausage and potatoes, tandoori chicken, chicken britto, Vienna schnitzels, tender tortillas, and fried chicken wings - were liked. The desserts single items-sandwiches, pineapples, waffles, pizza, bread with strawberry jam, mangoes, and tacoyaki - were liked. The combination menus - Italian, Indian, and American - were liked, but the southeast Asian menu was the least favored. Acceptance of combination and single menu items were similar. Male students liked multicultural menu items more than female students in all categories. Approximately 60% of dietitians had experience serving the single menu items for multicultural food service. The appropriate serving times were twice per month. Dietitians guessed that 80% of the students liked the multicultural menu. The dietitians preferred serving American or Chinese foods to southeast Asian food. There were two difficulties in serving the multicultural menu, which were voiced as as lack of skill in cooking the items and improper cooking utensils and tableware for the items. Despite all the difficulties, the dietitians served the multicultural menu because it provided menu diversity, rather than for educational reasons.

한국 전통 김치에 대한 중국인들의 기호도와 소비행태에 관한 연구 (Preference and Eating Activities of Chinese for Traditional Korean Kimchi)

  • 김은미;김영진;정미경
    • 한국식품영양과학회지
    • /
    • 제33권10호
    • /
    • pp.1641-1645
    • /
    • 2004
  • 본 조사연구는 중국인의 한국 김치에 대한 기호도와 중국 시장에서의 김치의 개선점, 중국 식생활에서 김치활용방법 등을 조사하여, 중국인의 식생활에 부합하여 한국 김치의 소비량을 증진시키는 방안과 김치의 현지화 방안을 조사하고자 실시하였으며 그 결과는 다음과 같다. 조사 대상 중국인들 중 한국김치를 시식한 경험이 있는 사람이 89.9%, 시식해 본 경험이 없는 사람이 10.1%로, 조사 대상자의 대부분이 김치를 시식한 경험이 있는 것으로 조사되었다. 배추김치에 대한 성별에 따른 기호도는 남자(M=3.61)가 여자(M=3.58)보다도 좋은 것으로 나타났으나 남녀간의 유의적 차이는 없었다. 김치의 전체적인 기호도에 영향을 미치는 요인으로는 맛(p<0.001), 외관(p<0.001), 조직감(p<0.05) 순으로 나타났다. 김치 시식후의 맛에 대해서는 "매운맛(34.3%)", "신맛(31.8%)이 느껴진다" 순으로, 조직감에 대해서는 "아삭거림(73.8%)", "질김(22.8%)", 향미에 대해서는 "매운 냄새(38.9%)", "신냄새(38.1%)"순으로 김치색에 대해서는 "빨간색(43.0%)", "노란색(25.6%)이 느껴진다"순으로 조사되었다. 한국 김치의 좋은 점에 대한 성별에 따른 차이는 남자의 경우 군덕내(22.4%)가 좋다. 건강식품이어서 좋다(22.4%), 매운맛이 좋다(20.7%)로 조사되었으며 여자의 경우 씹는 식감이 좋다(24.6%)로 가장 많고 군덕내가 좋다(23.4%)와 매운맛이 좋다(21.6%)로 남자와 비슷한 결과를 보였다. 반면 김치에 대한 개선점으로 질긴 질감의 저하(24.9%), 매운맛의 감소(20.5%), 군덕내의 저하(19.3%)로 조사되었다. 중국 음식 중에서 김치와 비슷한 음식으로 성채(xian cil)(23.2%), 작채(zha cai)(15.2%), 산채(Suan cai)(15.2%), 월채(12.8%), 사천포채(si chuan pao cil)(12.8%)라 응답하였고 기타 의견으로 한국 김치와 비슷한 것이 없다(8.8%)로 조사되었다. 중국 음식에 김치를 활용하였을 때 중국인들이 생각하는 김치의 용도는 고기 요리와 함께 섭취(31.7%), 밥, 국밥, 죽 등과 함께 섭취(29.9%), 요리의 부재료로 사용(18.5%)으로 조사되었으며 김치를 중국 요리의 부재료로 사용했을 시 적당한 중국 요리에 대한 조사에서는 죽(21.7%), 국밥(21.7%), 볶음밥(11.3%) 등으로 조사되었다.

충무공 이순신장군 사당의 불천위제례음식문화 비교 - 아산현충사고택·통영착량묘·남해충렬사 - (Comparison of Bulcheonwijerye Food Cultures in Shrines of Admiral Yi Sun-sin)

  • 박미연;강민경;조명희;최서율;박필숙
    • 한국식생활문화학회지
    • /
    • 제27권6호
    • /
    • pp.598-606
    • /
    • 2012
  • The aim of this study was to comparatively analyze the differences in Jinseol (ritual table-setting) and Jesu (ritual food) from the cultural perspective of ancestral ritual formalities regarding Bulcheonwijerye of Admiral Yi Sun-Sin, which is being held in Asan-hyeonchungsa shrine, Tongyeong-changnyangmyo and Namhae-chungyeolsa. The results are summarized as follows. A total of 32 types of Jemul (ritual food) in 6 rows in Asan-hyeonchungsa shrine, a total of 30 types of jemul in 6 rows in Tongyeong-changnyangmyo, and a total of 12 types of jemul in 2 rows in Namhae-chungyeolsa were prepared for the ritual table. In the Asan-hyeonchungsa shrine and Tongyeong-changnyangmyo, cooked foods have been used for jesu, whereas raw, uncooked foods have been used for jesu in Namhae-chungyeolsa. In the Asan-hyeonchungsa shrine, Gaeng (Kook) for liquid soup of Tang (stew) and Tang (5-tang) for the solid ingredient of stew have been prepared for a ritual table. In Tongyeong-changnyangmyo, fish Kook for Gaeng and So-tang (tofu stew) for Tang have been prepared for the ritual table. In Asan-hyeonchungsa shrine, Yukjeok (beef slices broiled on a skewer), Gyejeok (chicken jeok) and Eojeok (fish jeok) have been stacked together as Dojeok on a ritual table whereas in Tongyeong-changnyangmyo, Yukjeok, Sojeok and Eojeok have been placed on the ritual table as Pyunjeok (one by one). In Namhae- chungyeolsa, raw pork meat has been placed on the ritual table. As Po (a dried meat or fish), dried fish and dried seafood have been used in Tongyeong-changnyangmyo, whereas raw beef meat has been used in Namhae-chungyeolsa. Although Namul (cooked vegetables) and Mulkimchi (watery plain kimchi) are placed on ritual table for Asan-hyeonchungsa shrine, only Namul and Saengchae (raw vegetables) is used in Tongyeong-changnyangmyo and Namhae-chungyeolsa, respectively. Bulcheonwijerye for the same person, Admiral Yi Sun-Sin, has different characteristics according to the shrines. Accordingly, there is a need to preserve and succeed bulcheonwijerye of Admiral Yi because it is a traditional culture in ancestral rituals.

전통적 모유량 증가방법에 관한 연구 (Korean's Traditional Method to Increase the Amount of Breast Milk.)

  • 이미라;서연옥;조정호;김태임;박영숙;박송자;박인숙;박종숙;이혜경;임현빈;조동숙;주숙남;최상순
    • 모자간호학회지
    • /
    • 제3권2호
    • /
    • pp.142-152
    • /
    • 1993
  • In recent days, most of mothers prefer bottle feeding to breast feeding. Even mothers who started with breast feeding, change to bottle feeding in a short period. Many factors were reported causing the trend, but a significant influencing latter was revealed the mothers' perception that their breast milk wasn't enough for their babies. The purpose of this study were to identify how mothers of 30 years ago kept breastfeeding longer period for their child, and what were the diet they used in order to keep adequate breast milk secretion. The subjects of this study were 95 women who are over 60 years or older. Data were gathered by 13 authors by interview using structured questionnare. There were 16 questions related to subject's demographic informations and the specific recipe which they used, and 7 questions related to breast feeding techniques they used. Data were analyzed by SPSS/PC and content analysis. Results were as follows. 1. The subjects reflected that their milk secretion was enough to feed their tables. 2. More than half of the subject started breast feeding on the 3rd day after delivery and had continued breast feeding until they were pregnant again. 3. The subjects tried to eat as much rice and seaweed (MiYuk) soup as possible and didn't take any other specific diet during the breast feeding period. 4. The subjects didn't pay specific attention to the breast, general health. emotion, home environment. The only thing they did was being careful not to press breast when not feed. 5. Many subjects perceived that breast feeding made them healthy, and only 7% of subjects responded that they had some health problem during the breast feeding period.

  • PDF

엽삭젓 제조중의 미생물 및 화학성분의 변화 (Changes of Microbial and Chemical Components in Salt-fermented Youbsak during the Fermentation)

  • 양호철;정희종
    • 한국식품과학회지
    • /
    • 제27권2호
    • /
    • pp.185-192
    • /
    • 1995
  • 함평군 손불면의 특산물인 엽삭젓을 염농도 18%와 22%로 각각 엽삭젓을 제조하여 발효가 진행되는 동안 발효와 관련된 미생물과 여러가지 화학성분의 변화를 측정한 결과 발효 초기에 지질과 단백질의 감소와 총균수의 증가가 있었고 총산도의 증가는 어느정도 pH와 반비례적인 경향을 보였고, 아미노태질소와 지질의 산가는 급증한 후 큰 변화를 보이지 않았다. 선도의 척도라 할 수 있는 휘발성염기질소는 뼈국물을 넣어줌으로서 그 증가가 억제됨을 보이지만 전체적으로 볼때 발효 기간중 꾸준히 증가하였으며 염도 22% 엽삭젓보다는 염도 18% 엽삭젓이 훨씬 높은 수치를 보였다. 지방산 조성은 palmitic acid($C_{16:0}$)가 20% 정도 함유되어 가장 많았고, palmitoleic acid($C_{16:1}$), eicosapentaenoic acid($C_{20:5}$), oleic acid($C_{18:1}$), myristic acid($C_{14:0}$)순으로 함유되어 이들이 전체 지방산의 77.3%를 차지하였으며 EPA와 DHA도 약 20%정도 함유되어 있었으며 발효 기간중 큰 변화가 없었으며 염도에 따른 차이도 없었다. 총 유리아미노산도 휘발성 염기질소와 마찬가지로 계속 증가하지만 뼈국물을 넣고 젓국물 달여 붓기를 하므로서 상당히 그 증가의 지연이 이루어짐을 알 수 있었으며 유리아미노산 조성은 원료육의 경우 aspartic acid, threonine, histidine이 주류를 이루었으나 숙성된 염도 18% 엽삭젓의 경우는 leucine, tyrosine, glutamic acid, valine, isoleucine이, 염도 22% 엽삭젓의 경우는 alanine, glutamic acid, leucine, methionine이 주류를 이루었다. 이상의 결과를 비교해 볼때 엽삭젓에는 고도불포화지방산 특히 EPA가 많이 함유되어 있으며 염도 18%와 22%의 엽삭젓의 염도간에 큰 차이는 없었으나 VBN등의 변화에 있어서 엽삭젓 제조의 염도로는 18%에 비하여 22%가 더 적합한 것으로 생각되었다.

  • PDF

반가 식품인 청육장 제조 중 아이소플라본 분포 변화 (Changes in Isoflavone Profiles during Cheongyukjang Preparation, A Traditional Banga Food)

  • 이승욱;박영우;한양선;장판식;이종미;김영석;이재환
    • 한국식품과학회지
    • /
    • 제41권2호
    • /
    • pp.141-145
    • /
    • 2009
  • 청육장은 볶은 대두를 이용하여 제조된 청국장에 해산물, 육류를 함께 가열한 반가 식품의 일종이다. 140과 220$^{\circ}C$에서 각각 21.0과 6.0분 간 볶은 대두와 이를 이용한 청국장, 청육장의 총 아이소플라본을 HPLC로 분석하였다. 총 아이소플라본 함량(${\mu}$mol/g)은 생 대두 대비 약 79-80, 56-65, 47-50%이었다. 볶음 공정으로 인해 malonyl-${\beta}$-glucosides 함량은 유의적으로 감소한 반면 acetyl-${\beta}$-glucosides와 ${\beta}$-glucosides의 함량은 유의적으로 증가하였다(p<0.05). 청국장과 청육장의 주된 아이소플라본은 ${\beta}$-glucosides 이었다. 생 대두와 볶은 대두에서는 succinyl-${\beta}$-daidzin과 succinyl-${\beta}$-genistin은 검출되지 않았고, 청국장과 청육장에서 succinyl-${\beta}$-genistin의 peak area는 succinyl-${\beta}$-daidzin 보다 더 높게 검출되었다.

국내 쌀 가공식품의 개발현황과 당면과제 (Current Status and Recent Subjects of Rice Products Development in Korea)

  • 금준석
    • 한국식품저장유통학회:학술대회논문집
    • /
    • 한국식품저장유통학회 2002년도 창립 10주년 기념 국제학술심포지움
    • /
    • pp.109-119
    • /
    • 2002
  • Rice production in Korea began to rise significantly after 1970. Rice is the dominant food in Korea and most of the rice production (about 95%) is consumed as cooked rice. it provides over 4,000Kj of energy per capita per day. Apparent rice availability in 2000, 93.6Kg of milled rice per person annually. The non-allergenic character of rice offers a sound basis for development of products for markets for all age groups. Whole grains are washed rice, coated rice, enriched rice in Korea. Utilization of rice as food can be categorized three categories in Korea; direct food use, processed foods, and brewing. Rice for direct consumption include regular whole grain, precooked rice, brown rice and specialty products such as aseptic cooked rice, retort cooked rice and rice burger. Rice used for processed foods includes that for cereal, soup, baby food, snack, cake, noodle, brown rice tea, and minor unclassified uses. Rice use for brewing is for the production of fermented rice wine. The use of rice for direct food is by for the greatest of the three uses. Although direct food accounts for the largest domestic consumption, a significant quantity of rice is used in processed products. The use of rice by-products as human food should not be over looked. Utilization of by products(rice germ, rice bran) requires a specialized technology. Typical type of rice is black rice. When cooked, black rice gives a black color to cooked rice. Glutinous rice performs specific functions in several commercial products such as dessert, gravis, cake and snack. Rice starch production is quite limited because of the high cost of making of starch. Rice processed products in Korea are occupied small parts of total rice production compared to Japan. Rice cake (Garadog) is the principal from of rice product consumed in Korea. Rice cake and snack is usually prepared from non-glutinous milled by washing, grinding, steaming, cooling and packaging. Rice cake will be continued to be a major rice product in Korea. Rice products represent a means to study variety differences in rice grain quality, since the processing magnifies differences not normally detected from more boiling. Recently, rice processing companies in Korea are about 400 ones which uses rice about 160,000tons. New rice processed products and modified traditional products must be developed and diversified with high quality and processing properties of rice processed products are improved.

  • PDF

식품 중 결합형 3-MCPD 오염실태조사 (Survey of Contaminants of Bound 3-MCPD in Food)

  • 강영운;박성국;서정혁;김동술
    • 한국식품위생안전성학회지
    • /
    • 제25권4호
    • /
    • pp.289-293
    • /
    • 2010
  • 식품을 제조, 가공하는 과정 중 생성되는 3-MCPD (3-Monochloropropane-l,2-diol)는 식품 중 미량 존재하는 유해 물질로 우리나라에서는 산분해간장 빛 혼합간장과 산분해단백질 (HVP)에 기준을 설정하여 관리하고 있다. 3-MCPD 지방산에스테르라고도 불리는 결합형 3-MCPD는 지방산과 글리세라이드가 반응하여 생성되는 중간물질로서, 독일 연방위해 평가원(BfR)에서는 3-MCPD 지방산에스테르 자체의 독성이나 위해성에 대한 자료는 부족하지만, 인체내에 식품형태로 들어가서 가수분해될 때 3-MCPD가 생성될 수 있으므로 저감화 대책이 필요하다고 보고하고 있다. 따라서, 본 연구에서는 최근에 개발된 결합형 3-MCPD 분석법을 이용하여, 간장 등 장류 식품, 조미식품과 식육가공품 등 209건에 대해 결합형 3-MCPD 함량조사를 실시한 결과, 전체 209건의 검체 중에서 장류의 경우 44건의 검체 중에서 8건에서 결합형 3-MCPD가 검출되었고(0.02~0.28ppm), 스프 12건 종 8건에서 결합형 3-MCPD가 검출되었다(0.01~0.96ppm). 소스는 60건 중 22건에서 결합형 3-MCPD가 검출되었으며(0.01~0.55ppm), 식육가공품의 경우 총 30건의 검체 중 16건에서 결합형 3-MCPD가 검출되었다(0.04~0.l8ppm). 스낵과자에서는 28건 중 20건에서 결합형 3-MCPD가 검출되었고(0.09~1.43ppm), 유탕면제품 10건 중 8건에서 검출되었다(0.04~1.22ppm). 견과류가공품 10건 중 6건에서 결합형 3-MCPD가 검출되었으며 (0.06~0.25ppm), 식물성크림에서는 15건 중 1건에서 결합형 3-MCPD가 0.05ppm이 검출되었다. 이상의 검출수준은 제외국과 비교할 때 낮은 수준이었다.

한.중.일 세시풍속과 세시음식(歲時飮食)에 대한 비교 (Comparative Study on Seasonal Festival and Food Culture among the Korea, China and Japan)

  • 신미경;정희정
    • 동아시아식생활학회지
    • /
    • 제18권3호
    • /
    • pp.277-293
    • /
    • 2008
  • We conducted a consensual, expansive, and successive study to compare cultural differences and similarities between Korean, Chinese and Japanese's Seasonal Festivals and Foods documentarily. It showed interesting results that the three countries had celebrated with similar meanings, and shared similar events and special foods. Seasonal Festivals happen throughout the year sequentially: the New Year Day, January $15^{th}$(first full moon festival), March $3^{rd}$(double three day), May $5^{th}$(double five day), July $7^{th}$(double seven day) and finally the Year Farewell Festival. While, the festival of a royal birthday of Buddha happens on April $8^{th}$ in both countries: Korea and Japan. There is also one of the big festivals called the harvest moon festival on August $15^{th}$, and this event celebrates with special foods both in Korea and China. On December $23^{th}$, it is a special day for both Chinese and Japanese, but they celebrate the day with different meanings to it. Three countries have a special seasonal event celebrated each other. Koreans have a special event called Sambok to overcome summer with special food during a middle of June to the beginning of July. Chinese have a special event for overcoming winter with soup on December $8^{th}$. Japanese have a special event with rice cake to safety on January $11^{th}$. On these seasonal festivals, it is different to note that two different kinds of calendars are used. The lunar calendar is used by Koreans and Chinese whereas the solar calendar is used by Japanese. Because of the similarity in Buddhism, and agricultural industry, and especially sharing Chinese Characters in words, these three countries have in common in many ways to celebrate Seasonal Festival, and it is very unique custom in the world. Nowadays; however, these traditional events and special foods are changing in more simplified version and almost disappearing in all three countries. Therefore, we suggest that the Seasonal Festivals and Foods should be more emphasized in flourishing and exchanging between Korea, China and Japan.

  • PDF

유청단백질로 만들어진 식품포장재에 관한 연구

  • 김성주
    • 한국유가공학회:학술대회논문집
    • /
    • 한국유가공기술과학회 2002년도 제54회 춘계심포지움 - 우유와 국민건강
    • /
    • pp.59-60
    • /
    • 2002
  • Edible films such as wax coatings, sugar and chocolate covers, and sausage casings, have been used in food applications for years$^{(1)}$ However, interest in edible films and biodegradable polymers has been renewed due to concerns about the environment, a need to reduce the quantity of disposable packaging, and demand by the consumer for higher quality food products. Edible films can function as secondary packaging materials to enhance food quality and reduce the amount of traditional packaging needed. For example, edible films can serve to enhance food quality by acting as moisture and gas barriers, thus, providing protection to a food product after the primary packaging is opened. Edible films are not meant to replace synthetic packaging materials; instead, they provide the potential as food packagings where traditional synthetic or biodegradable plastics cannot function. For instance, edible films can be used as convenient soluble pouches containing single-servings for products such as instant noodles and soup/seasoning combination. In the food industry, they can be used as ingredient delivery systems for delivering pre-measured ingredients during processing. Edible films also can provide the food processors with a variety of new opportunities for product development and processing. Depends on materials of edible films, they also can be sources of nutritional supplements. Especially, whey proteins have excellent amino acid balance while some edible films resources lack adequate amount of certain amino acids, for example, soy protein is low in methionine and wheat flour is low in lysine$^{(2)}$. Whey proteins have a surplus of the essential amino acid lysine, threonine, methionine and isoleucine. Thus, the idea of using whey protein-based films to individually pack cereal products, which often deficient in these amino acids, become very attractive$^{(3)}$. Whey is a by-product of cheese manufacturing and much of annual production is not utilized$^{(4)}$. Development of edible films from whey protein is one of the ways to recover whey from dairy industry waste. Whey proteins as raw materials of film production can be obtained at inexpensive cost. I hypothesize that it is possible to make whey protein-based edible films with improved moisture barrier properties without significantly altering other properties by producing whey protein/lipid emulsion films and these films will be suitable far food applications. The fellowing are the specific otjectives of this research: 1. Develop whey protein/lipid emulsion edible films and determine their microstructures, barrier (moisture and oxygen) and mechanical (tensile strength and elongation) properties. 2. Study the nature of interactions involved in the formation and stability of the films. 3. Investigate thermal properties, heat sealability, and sealing properties of the films. 4. Demonstrate suitability of their application in foods as packaging materials. Methodologies were developed to produce edible films from whey protein isolate (WPI) and concentrate (WPC), and film-forming procedure was optimized. Lipids, butter fat (BF) and candelilla wax (CW), were added into film-forming solutions to produce whey protein/lipid emulsion edible films. Significant reduction in water vapor and oxygen permeabilities of the films could be achieved upon addition of BF and CW. Mechanical properties were also influenced by the lipid type. Microstructures of the films accounted for the differences in their barrier and mechanical properties. Studies with bond-dissociating agents indicated that disulfide and hydrogen bonds, cooperatively, were the primary forces involved in the formation and stability of whey protein/lipid emulsion films. Contribution of hydrophobic interactions was secondary. Thermal properties of the films were studied using differential scanning calorimetry, and the results were used to optimize heat-sealing conditions for the films. Electron spectroscopy for chemical analysis (ESCA) was used to study the nature of the interfacial interaction of sealed films. All films were heat sealable and showed good seal strengths while the plasticizer type influenced optimum heat-sealing temperatures of the films, 130$^{\circ}$C for sorbitol-plasticized WPI films and 110$^{\circ}$C for glycerol-plasticized WPI films. ESCA spectra showed that the main interactions responsible for the heat-sealed joint of whey protein-based edible films were hydrogen bonds and covalent bonds involving C-0-H and N-C components. Finally, solubility in water, moisture contents, moisture sorption isotherms and sensory attributes (using a trained sensory panel) of the films were determined. Solubility was influenced primarily by the plasticizer in the films, and the higher the plasticizer content, the greater was the solubility of the films in water. Moisture contents of the films showed a strong relationship with moisture sorption isotherm properties of the films. Lower moisture content of the films resulted in lower equilibrium moisture contents at all aw levels. Sensory evaluation of the films revealed that no distinctive odor existed in WPI films. All films tested showed slight sweetness and adhesiveness. Films with lipids were scored as being opaque while films without lipids were scored to be clear. Whey protein/lipid emulsion edible films may be suitable for packaging of powder mix and should be suitable for packaging of non-hygroscopic foods$^{(5,6,7,8,)}$.

  • PDF