Cooking Innovations

Cooking Innovations

ספרו החמישי של המחבר, שהתפרסם בהוצאת  CRC היוקרתית:

Cooking Innovations

הספר נכתב בשיתוף עם פרופ' מדוקה הירשימה מיפן.

Cooking Innovations:
Using Hydrocolloids for Thickening, Gelling, and Emulsification
Amos Nussinovitch  & Madoka Hirashima
Hardcover: 384 pages; Publisher: CRC Press; 1 edition (9 Oct 2013);
Language: English ISBN-10: 143987588X; ISBN-13: 978-1439875889

Book Description

While hydrocolloids have been used for centuries, it took molecular gastronomy to bring them to the forefront of modern cuisine. They are among the most commonly used ingredients in the food industry, functioning as thickeners, gelling agents, texturizers, stabilizers, and emulsifiers. They also have applications in the areas of edible coatings and flavor release. Although there are many books describing hydrocolloids and their industrial uses, Cooking Innovations: Using Hydrocolloids for Thickening, Gelling, and Emulsification is the first scientific book devoted to the unique applications of hydrocolloids in the kitchen, covering both past uses and future innovations.

Each chapter addresses a particular hydrocolloid, protein hydrocolloid, or protein–polysaccharide complex. Starting with a brief description of the chemical and physical nature of the hydrocolloid, its manufacture, and its biological/toxicological properties, the emphasis is on practical information for both the professional chef and amateur cook. Each chapter includes recipes demonstrating the particular hydrocolloid’s unique abilities in cooking. Several formulations were chosen specifically for food technologists, who will be able to manipulate them for large-scale use or as a starting point for novel industrial formulations.

The book covers the most commonly used hydrocolloids, namely, agar–agar, alginates, carrageenan and furcellaran, cellulose derivatives, curdlan, egg proteins, galactomannans, gelatin, gellan gum, gum arabic, konjac mannan, pectin, starch, and xanthan gum. It also discusses combining multiple hydrocolloids to obtain novel characteristics. This volume serves to inspire cooking students and introduce food technologists to the many uses of hydrocolloids. It is written so that chefs, food engineers, food science students, and other professionals will be able to cull ideas from the recipes and gain an understanding of the capabilities of each hydrocolloid.

Fertility problems? Joining the ‘breakfast club’ can help, say researchers from the from Hebrew and Tel Aviv Universities

Eating more calories in the morning, rather than evening, shown to assist in overcoming reproductive difficulties

Jerusalem, Oct. 1, 2013 – A new study by researchers at the Hebrew University of Jerusalem and Tel Aviv University reveals that eating a good breakfast can have a positive impact on women with problems of infertility.

In recent years, nutritional research has found that our weight is affected not only by the level of calorie intake, but also by the question of when to consume large amounts of calories.

Prof. Oren Froy

Prof. Oren Froy

Now, research, conducted by Prof. Oren Froy, director of the Nutrigenomics and Functional Foods Research Center at the Robert H. Smith Faculty of Agriculture, Food and Environment of the Hebrew University, and Ma’ayan Barnea, plus Prof. Daniela Jocabovitz and Dr. Julio Weinstein from Tel Aviv University and Wolfson Medical Center, shows that a big breakfast increases fertility among woman who suffer from menstrual irregularities.

The study examined whether meal times have an impact on the health of woman with menstrual irregularities due to Polycystic Ovary Syndrome (PCOS). PCOS affects approximately 6-10% of woman of reproductive age, disrupting their reproductive abilities. This syndrome creates a resistance to insulin, leading to an increase in male sex hormones (androgens), and can also cause menstrual irregularities, hair loss on the scalp though increase in body hair, acne, fertility problems and future diabetes.

The experiment was carried out at Wolfson Medical Center on 60 women over a 12-week period. The women, from the ages of 25 to 39, were thin with a BMI (body mass index) of less than 23 and suffered from PCOS.

The women were divided into two groups and were allowed to consume about 1,800 calories a day. The difference between the groups was the timing of their largest meal. One group consumed their largest meal, approximately 980 calories, at breakfast, while the other at dinner. Researchers wanted to examine whether the schedule of calorie intake affects insulin resistance and the increase in androgens among woman suffering from PCOS. The women kept records of exactly what they ate.

The findings, recently published in the journal, “Clinical Science,” showed improved results for the group that consumed a big breakfast. Glucose levels and insulin resistance decreased by 8%, while the second group (“dinner”) showed no changes. Another finding showed that among the “breakfast” group, testosterone (one of the androgens) levels decreased by nearly 50%, while the “dinner” group level stayed neutral. In addition, there was a much higher rate of ovulating woman within the “breakfast group” compared to the “dinner” group, showing that eating a hearty breakfast leads to an increase in the level of fertility among woman with Polycystic Ovary Syndrome.

According to Prof. Froy, “The research clearly demonstrates that indeed the amount of calories we consume daily is very important, but the timing as to when we consume them is even more important.”

11 בנובמבר, 2012

פחמימות חכמות: מחקר חדש מצא שריכוז הפחמימות לשעות הערב מגביר את תחושת השובע במהלך היום ומפחית את הסיכון לסוכרת ולמחלות לב וכלי דם

פחמימות בשעות הערב תורמות לדיאטה

פחמימות בשעות הערב תורמות לדיאטה
דיאטה המבוססת על מתן הפחמימות בצורה מרוכזת בשעות הערב עשויה לגרום להיפוך עקומות הפעילות של ההורמונים שאחראים לתחושות הרעב והשובע ולהפחית את גורמי הסיכון לסוכרת ולמחלות לב וכלי דם, כך מצא מחקר חדש שבוצע במכון לביוכימיה, מדעי המזון ותזונת האדם בפקולטה לחקלאות, מזון וסביבה ע"ש רוברט ה' סמית' באוניברסיטה העברית.

במחקר, שביצעה תלמידת המחקר סיגל סופר בהנחייתו של פרופ' אמריטוס זכריה מדר (כיום המדען הראשי במשרד החינוך והתרבות), השתתפו 78 שוטרים שהוקצו אקראית לדיאטת המחקר או לדיאטת ביקורת למשך שישה חודשים. החוקרים בדקו את השפעתה של דיאטת המחקר על שלושה הורמונים: לפטין, "הורמון השובע", שרמתו בדם בדרך כלל נמוכה במהלך היום וגבוהה במהלך הלילה; גרלין, "הורמון הרעב", שרמתו בדם בדרך כלל גבוהה במהלך היום ונמוכה במהלך הלילה; ואדיפונקטין, הורמון המקטין את התפתחותם של גורמי הסיכון לסוכרת ולמחלות לב וכלי דם.

"מחקרים שנעשו על מוסלמים בתקופת הרמדאן, כאשר הם צמים ביום ואוכלים ארוחות עתירות פחמימות בערב, הראו שעקומת הפעילות של הלפטין - הורמון השובע - משתנה לעומת מה שניתן למצוא באדם שאוכל באופן מאוזן לאורך כל היממה", מסביר פרופ' מדר.

החוקרים מצאו שבנבדקים שעשו את דיאטת המחקר, בה צריכת הפחמימות מרוכזת בערב, עקומות הפעילות של הורמון הרעב והורמון השובע התהפכו יחסית לפעילותם הרגילה, מה שהביא לתחושת שובע במהלך היום ואפשר לנבדקים להתמיד במשטר הדיאטה. בעקבות כך התקבל שיפור במדדים האנטרופומטריים (משקל, היקף בטן, אחוז שומן). עוד הם מצאו שרמתו של הורמון האדיפונקטין עלתה בקבוצה זו ואיתה נצפה שיפור ברמות הסוכר, השומנים בדם ובמדדי הדלקת".

הממצאים מראים שישנו יתרון בריכוז צריכת הפחמימות בשעות הערב, במיוחד עבור אנשים הנמצאים בסיכון לפתח סוכרת או מחלות לב וכלי דם בשל השמנת יתר. "ממצאי המחקר מניחים את הבסיס לחלופה תזונתית ראויה יותר עבור אנשים אלה, המתקשים להתמיד בדיאטות לאורך זמן מוסיף פרופ' מדר. "השלב הבא הוא להבין מהם המנגנונים שהובילו לתוצאות שהתקבלו".

11 November, 2012
New research: limiting carbs to dinner-time increases satiety, reduces risk for diabetes and cardiovascular disease
Carbs at night: a possible alternative for people who have difficulty persisting in diets

Carbs at night: a possible alternative for people who have difficulty persisting in diets

An experimental diet with carbohydrates eaten mostly at dinner could benefit people suffering from severe and morbid obesity, according to new research at the Hebrew University of Jerusalem.

The diet influences secretion patters of hormones responsible for hunger and satiety, as well as hormones associated with metabolic syndrome. In this way the diet can help dieters persist over the long run, and reduce risk factors for diabetes and cardiovascular disease.

The research was carried out by research student Sigal Sofer under the auspices of Prof. (Emeritus) Zecharia Madar, at the Institute of Biochemistry, Food Science and Nutrition at the Hebrew University's Robert H. Smith Faculty of Agriculture, Food and Environment. (Prof. Madar is now Chief Scientist at Israel’s Ministry of Education.)

Sofer randomly assigned 78 police officers to either the experimental diet (carbohydrates at dinner) or a control weight loss diet (carbohydrates throughout the day). 63 subjects finished the six-month program.

The researchers examined the experimental diet's effect on the secretion of three hormones: leptin, considered to be the satiety hormone, whose level in the blood is usually low during the day and high during the night; ghrelin, considered the hunger hormone, whose level in the blood is usually high during the day and low during the night; and adiponectin, considered the link between obesity, insulin resistance and the metabolic syndrome, whose curve is low and flat in obese people.

"The idea came about from studies on Muslims during Ramadan, when they fast during the day and eat high-carbohydrate meals in the evening, that showed the secretion curve of leptin was changed,” explained Prof. Madar.

The researchers found that the innovative dietary manipulation led to changes in daylight hormonal profiles in favor of the dieters: the satiety hormone leptin’s secretion curve became convex during daylight hours with a nadir in the late day; the hunger hormone ghrelin’s secretion curve became concave, peaking only in the evening hours; and the curve of adiponectin, considered the link between obesity, insulin resistance and the metabolic syndrome, was elevated. At the same time this dietary pattern led to lower hunger scores, and better anthropometric (weight, abdominal circumference and body fat), biochemical (blood sugar, blood lipids) and inflammatory outcomes compared to the control group.

The findings suggest there is an advantage in concentrating carbohydrate intake in the evening, especially for people at risk of developing diabetes or cardiovascular disease due to obesity. "The findings lay the basis for a more appropriate dietary alternative for those people who have difficulty persisting in diets over time," said Prof. Madar. "The next step is to understand the mechanisms that led to the results obtained."

The study was published in two continuous papers: "Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner" (published in Obesity) and "Changes in daily leptin, ghrelin and adiponectin profiles following a diet with carbohydrates eaten at dinner in obese subjects" (published in Nutrition, Metabolism & Cardiovascular Diseases).

Sources of support for the study include Meuhedet Medical Services, Israel; the Israeli Police Force; the Kaplan Medical Center in Rehovot, Israel (for Dr. Fink); the Israel Diabetes Association; and the Israel Lung and Tuberculosis Association (for Prof. Eliraz).

Yissum Introduces a Novel Biocontrol Method for Protecting Plants from Pathogens Using Yeast Isolated from Strawberry Leaves

Novel biocontrol agent is environmentally-friendly, non-toxic and effective for a large variety of plants

Jerusalem, Israel, July 23, 2012 - Agriculture relies heavily on the use of pesticides in order to maximise crop yield. However, the widespread use of chemical pesticides has resulted in severe environmental pollution, and many pathogens are developing resistance to existing chemicals. In addition, many pesticides are now banned for use, and organic farming is not allowed to rely on such substances at all. A major goal, therefore, is to develop new, environmentally-friendly tools to control pathogens.

Now, Yissum Research and Development Company of the Hebrew University of Jerusalem, introduces a novel biocontrol agent that is based on naturally-occurring fungi that increase the plant's resistance to fungal and bacterial infestations as well as enhances growth. The new biocontrol agent has a complex mode of action that reduces pathogens' ability to develop resistance. The invention was patented by Yissum, which is currently searching for an appropriate partner for the further development and commercialization of the product.

The novel biocontrol agent was developed by Dr. Maggie Levy, from the Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment at the Hebrew University. It is based on a species of the epiphytic yeast Pseudozyma that isolated from strawberry leaves. Dr. Levy and her team showed that this yeast secretes substances which inhibit several fungal and bacterial pathogens. Application of the yeast spores significantly abolished growth of different fungal causal agents of plant diseases such as powdery mildews, the gray mold that has more than 400 different hosts, crown rust, the black spot disease of cultivated Brassicas and late wilt disease in corn. Pathogenic bacteria such as Clavibacter michiganensis the causative agent of bacterial canker of tomato were also inhibited by the yeast.

"Fungal biocontrol agents have become an important alternative to the use of chemicals due to environmental concerns. The complex mode of action of biocontrol agents reduces the likelihood that pathogens will develop resistance to them," said Yaacov Michlin, CEO of Yissum. "The novel biocontrol agent developed in the lab of Dr. Levy is easy to produce, non-toxic and effective at low concentrations, and will serve to reduce the amount of chemicals required for pathogen control. This, in turn, would genuinely benefit farmers, consumers and the environment."


Jerusalem and Rehovot, Israel; Seoul, South Korea, May 29, 2012 — The discovery of a mummified Korean child with relatively preserved organs enabled an Israeli-South Korean scientific team to conduct a genetic analysis on a liver biopsy which revealed a unique hepatitis B virus (HBV) genotype C2 sequence common in Southeast Asia.

 mummified child with unique hepatitis B virus

mummified child with unique hepatitis B virus

Additional analysis of the ancient HBV genomes may be used as a model to study the evolution of chronic hepatitis B and help understand the spread of the virus, possibly from Africa to East-Asia. It also may shed further light on the migratory pathway of hepatitis B in the Far East from China and Japan to Korea as well as to other regions in Asia and Australia where it is a major cause of cirrhosis and liver cancer.

The reconstruction of the ancient hepatitis B virus genetic code is the oldest full viral genome described in the scientific literature to date. It was reported in the May 21 edition of the scientific journal Hepathology by a research team from the Hebrew University of Jerusalem’s Koret School of Veterinary Medicine, the Robert H. Smith Faculty of Agriculture, Food and Environment; the Hebrew University’s Faculty of Medicine, the Hadassah Medical Center’s Liver Unit; Dankook University and Seoul National University in South Korea.

Carbon 14 tests of the clothing of the mummy suggests that the boy lived around the 16th century during the Korean Joseon Dynasty. The viral DNA sequences recovered from the liver biopsy enabled the scientists to map the entire ancient hepatitis B viral genome.

Using modern-day molecular genetic techniques, the researchers compared the ancient DNA sequences with contemporary viral genomes disclosing distinct differences. The changes in the genetic code are believed to result from spontaneous mutations and possibly environmental pressures during the virus evolutionary process. Based on the observed mutations rates over time, the analysis suggests that the reconstructed mummy’s hepatitis B virus DNA had its origin between 3,000 to 100,000 years ago.

The hepatitis B virus is transmitted through the contact with infected body fluids , i.e. from carrier mothers to their babies, through sexual contact and intravenous drug abuse. According to the World Health Organization, there are over 400 million carriers of the virus worldwide, predominantly in Africa, China and South Korea, where up to 15 percent of the population are cariers of the virus. In recent years, universal immunization of newborns against hepatitis B in Israel and in South Korea has lead to a massive decline in the incidence of infection.

The findings are the result of a collaborative effort between Dr. Gila Kahila Bar-Gal of the Hebrew University of Jerusalem’s Koret School of Veterinary Medicine; Prof. Daniel Shouval of the Hadassah Medical Center’s Liver Unit and Hebrew University; Dr. Myeung Ju Kim of Dankook University, Seok Ju Seon Memorial Museum; Dr. Dong Hoon Shin of Seoul National University, College of Medicine ; Prof Mark Spigelman of the Hebrew University’s Dept. of Parasitology and Dr. Paul R. Grant of University College of London, Dept. of Virology.

Tracing hepatitis B virus to the 16th century in a Korean mummy. Kahila Bar-Gal G, Kim MJ, Klein A, Shin DH, Oh CS, Kim JW, Kim TH, Kim SB, Grant PR, Pappo O, Spigelman M, Shouval D. Hepatology. 2012 May 21. doi: 10.1002/hep.25852. [Epub ahead of print]

Consortium includes Prof. Dani Zamir of the Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem

Jerusalem, May 30, 2012 – The tomato genome sequence – both the domesticated type and its wild ancestor, Solanum pimpinellifolium — has been sequenced for the first time by a large international team of scientists, including a researcher from the Hebrew University of Jerusalem.

The achievement – an important tool for further development of better tomato production — by the 300-plus-member Tomato Genome Consortium (TGC) is reported on in the May 31 issue of the journal Nature.

The consortium includes Prof. Dani Zamir of the Robert H. Smith Faculty of Agriculture, Food and Environment of the Hebrew University. Other scientists in the project are from Argentina, Belgium, China, France, Germany, India, Italy, Japan, South Korea, Spain, the Netherlands, the United Kingdom and the United States.

When Columbus brought tomato seed from America to the old world some 500 years ago, he probably never imagined that it would be such a major contributor to human nutrition, health, culinary pleasure and international cooperation.

This latest leap in knowledge of the tomato genetic code (35,000 genes) provides a means to match DNA sequences with specific traits that are important for human well being or taste, such as flavor, aroma, color and yield.

Beyond improvement of the tomato, the genome sequence also provides a framework for studying closely related plants, such as potato, pepper, petunia and even coffee. These species all have very similar sets of genes, yet they look very different.

How can a similar set of “genetic blueprints” empower diverse plants with different adaptations, characteristics and economic products? This challenging question is being explored by comparing biodiversity and traits of tomato and its relatives.

The Tomato Genome Consortium started its work in 2003, when scientists analyzed the DNA sequence of tomato using the most modern equipment available at the time. Fortunately, with the recent introduction of so-called “next generation sequencing” technologies, the speed of data output increased 500-fold and enabled the project to move on efficiently to its conclusion.

Shaul Lapidot

Shaul Lapidot

Hebrew University student turns paper mill waste into ‘green’ material for industrial applications

Jerusalem, August 1, 2011 – A method to use paper millwaste to produce ecologically friendly, industrial foams from renewable resources has been developed by a graduate student in agriculture at the Hebrew University of Jerusalem.

Foams are used for numerous day-to-day uses, including in the manufacture of furniture and car interiors. In many composite material applications, they are used as core material in “sandwich” panels to achieve high strength, weight reduction, energy dissipation and insulation. Conventional foams are produced from polymers such as polyurethane, polystyrene, polyvinylchloride (PVC) and polyethylene terephthalate (PET). Since all of these current foams rely on fossil oil, they present a clear environmental disadvantage.

Shaul Lapidot, a Ph.D. student of Prof. Oded Shoseyov, along with his laboratory colleagues at the Robert H. Smith Faculty of Agriculture, Food and Environment of the Hebrew University in Rehovot, has formulated a procedure for production of nano-crystalline cellulose (NCC) from paper mill waste. NCC is further processed into composite foams for applications in the composite materials industry as bio-based replacement for synthetic foams.

The process of paper production involves loss of all fibers with dimensions lower than the forming fabric mesh. Consequently around 50% of the total fibers initially produced are washed away as sludge. In Europe alone, 11 million tons of waste are produced annually by this industry, creating an incentive for finding alternative uses and different applications for the wastes.

Lapidot has found that fibers from paper mill sludgeare a perfect source for NCC production due to their small dimensions which require relatively low energy and chemical input in order to process them into NCC. He also developed the application of NCC into nano-structured foams. This is further processed into composite foams for applications in the composite materials industry to be used as bio-based replacement for synthetic foams.

NCC foams that Lapidot and his colleagues have recently developed are highly porous and lightweight. Additional strengthening of the foams was enabled by infiltration of furan resin, a hemicellulose-based resin produced from raw crop waste, such as that remaining from sugar cane processing, as well as oat hulls, corn cobs and rice hulls.

The new NCC reinforced foams display technical performance which matches current high-end synthetic foams. The technology was recently licensed from Yissum, the technology transfer company of the Hebrew University, by Melodea Ltd., an Israeli-Swedish start-up company which aims to develop it for industrial scale production.

Lapidot’s development has led to his being awarded one of the Barenholz Prizes that were presented on June 21 at the Hebrew University Board of Governors meeting. The award is named for its donor, Prof. Yehezkel Barenholz of the Hebrew University-Hadassah Medical School.

Kwansimah Quansah completed her M.Sc. at the Division of External Studies  at the Robert H. Smith Faculty of Agriculture Food and Environment, and her tuition was generously supported by the Pears Foundation .

Read about her in the Jerusalem Post:
Israel growing on Ghanaian agricultural student

African native plans to improve farming standards in her homeland.

Hebrew University's Prof. Alexander Vainstein has developed a clever way to improve the genome of plants. By infecting plants with a modified virus, the plant DNA can be "edited" in a very specific manner. The breakthrough technique was announced by Yissum Research Development Company Ltd., Hebrew University's technology transfer company, and Danziger Innovations Ltd.

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