Agro articles in English Agriculture

Mandarin Oranges:
Protecting the Flavor
of This Popular Fruit

These clementine oranges are a type of mandarin orange.Fresh and juicy mandarin oranges are good for you and have a delightfully sweet flavor that makes them a favorite of kids and adults alike.

Whether you know them by brand names such as “Cuties” or “Halos,” or perhaps simply as clementines or tangerines, all are mandarins. And all are high in vitamin C and are a good source of vitamin A.

Agricultural Research Service scientist Dave Obenland at Parlier, California, and horticulturist Mary Lu Arpaia and colleagues at the University of California-Riverside are conducting studies to discover more about mandarin flavor and—equally as important—how to protect it as these oranges make their way from the orchard to the fruit bowl on your kitchen counter.

Their research focuses on uncovering more details about the natural chemicals in mandarins that contribute to the fruit’s pleasing flavor and on determining what causes changes in those flavors after the fruit is put into storage. That new knowledge may help citrus-fruit breeders, and the people who grow, store, ship, or sell the fruit, ensure that the oranges keep their delicious taste.

Chilling Out
Most mandarin oranges that are destined for the produce section of your local supermarket probably spend at least some time in cold storage. Before that happens, however, freshly picked mandarins are typically washed, then sprayed with a thin coating of a wax that’s approved for this food use. The wax helps hold in the fruit’s natural moisture and adds an attractive gloss to its peel.

Plant physiologist David Obenland adds mandarin juice to a vial for analysis of aroma volatiles. Next, the oranges are placed in cardboard cartons that are then stacked, in packinghouse storerooms, to await shipment.
The flavor research that Obenland and Arpaia began in 2009 may be among the most extensive of its kind for this specialty citrus fruit. The scientists have now tested more than 19,000 mandarin oranges from at least a half-dozen different research and commercial orchards in California, the state that produces the bulk of the nation’s mandarin harvest.

Individual studies have spanned multiple years and multiple harvests, to take within-year and year-to-year variations into account.

All of their experiments simulate real-world conditions of busy commercial packinghouses or retail settings and encompass a range of time-and-temperature regimens. In some of these tests, for instance, the researchers kept the fruit at cold-storage temperatures of 32, 39, 41, 46, or 50 °F for several weeks and, in some cases, followed that by a week or more of storage at 68 ËšF.

Storage experiments lasted up to 6 weeks and have yielded more than 5,000 data points. The work has included not just the classic W. Murcott Afourer variety, but lesser known ones, as well.

Some storage-related mandarin flavor research, done by scientists elsewhere, “treated cold storage followed by warmer storage as a single regimen,” Obenland says. “We evaluated the effects of the cold-storage period separately from the effects of the warm storage that followed. This work is, to the best of our knowledge, unique among published scientific studies of mandarin flavor. We found that cold-storage temperatures influence flavor in some varieties, but not others.”

An example: The 10 to 17 taste testers that evaluated mandarins for the research reported that the flavor of W. Murcott Afourer fruit stored at 46 °F for 3 to 6 weeks, followed by a week at 68 °F, was “slightly superior” to that of fruit of that same variety stored at 32 or 39 °F, followed by a week at 68 °F. However, the taste testers did not discern a difference in the flavor of Owari variety mandarins that were stored at these regimens.

What Makes Flavor?
Postdoctoral researcher Nittaya Ummarat sets up a device that traps aroma volatiles from mandarin juice for analysis by gas chromatography.In some experiments, loss of some flavor was attributed to changes in levels of a few specific chemicals. But the exact biological and chemical mechanisms underlying those changes are, for the most part, not well known and are a target of the team’s research.

For instance, the scientists found that statistically significant changes in several flavor-associated chemicals occurred after W. Murcott Afourer mandarins, previously refrigerated at 41 °F, were brought out of the cold and kept at 68 °F.

For that study, Obenland and Arpaia tracked changes in more than two dozen natural chemicals—alcohols, aldehydes, esters, and terpenes, also known as “aroma volatiles”—to learn more about the exact role each may play in the fruit’s flavor profile.

In brief, changes in a class of esters—the ethyl esters—occurred soon after the oranges were taken out of cold storage. Statistically significant increases in three of the four monitored ethyl esters (ethyl acetate, ethyl propanoate, and ethyl 2-methylpropanoate) took place within the first 24 hours after the fruits were moved from cold (41 °F) to warmer (68 °F) storage. What’s more, statistically significant increases in the fourth ethyl ester, ethyl 2-methylbutanoate, took place a day later.

Biological science technician Paul Neipp obtains a mandarin juice sample for analysis of aroma volatiles.Interestingly, all four ethyl esters are thought to contribute to a sweet, fruity aroma, which may have a role in what we perceive as flavor.

However, in the case of these ethyl esters, it may be possible to have too much of a good thing. That’s because high levels of these four compounds are suspected of contributing to off-flavor, Obenland says. The team’s ongoing studies may help clarify the impact of these ethyl esters in relation to other natural compounds.

Obenland and Arpaia also looked at two other important groups of flavor-related chemicals—sugars and acids. Their data suggests that increased concentrations of esters and alcohols “may have a greater influence on mandarin off-flavor than the ratio of sugars to acids,” Obenland says.

In new research, the scientists are looking at how flavor of W. Murcott Afourer and nine other mandarin varieties changes after the conventional wax-coating process. The coating limits movement of oxygen into the fruit. That can, in turn, lead to buildup of some flavor chemicals. But Obenland says a change in oxygen levels inside the fruit doesn’t explain every change in flavor.

In these experiments, mandarin varieties that are the least affected by the coating, or not affected at all, may be of the most interest. Their flavor secrets might help make mandarin oranges—already delectable—even better.
The research team’s findings were published in Postharvest Biology and Technology in 2011 and 2013.—By Marcia Wood, Agricultural Research Service Information Staff.

In the photos:

1. These clementine oranges are a type of mandarin orange. ARS scientists are studying cold-storage temperatures and more to make sure this popular fruit is as tasty as possible for you.

Photo by Peggy Greb.

2. Plant physiologist David Obenland adds mandarin juice to a vial for analysis of aroma volatiles. The identity and amount of these natural compounds are important in determining their contribution to the flavor of whole, fresh mandarins.

Photo by Nittaya Ummarat.

3. Postdoctoral researcher Nittaya Ummarat sets up a device that traps aroma volatiles from mandarin juice for analysis by gas chromatography.

Photo by David Obenland.

4. Biological science technician Paul Neipp obtains a mandarin juice sample for analysis of aroma volatiles.

Photo by Nittaya Ummarat.

Thanks to our friends at Agricultural Research Service!

Larisa English Club Explained

written by Billgreen54 ESL Tutor

Larisa English Club is all about you; students of the English language. Your desire to study and speak great English is why we have created this on-line English resource.


Larisa English Club is a work in progress from years of experience in the classroom. Professional English teachers and students contribute to our English Club with ideas and experiences.


Our website has content created for learners of a second language. Free resources for students as well as teachers of the English language is our main goal.

Video files from Larisa English ClubVideos are posted often and provide English learners with information all about the English language. English videos should be viewed as supplements to your daily dose of English language study.


We encourage comments and language requests from students and teachers alike. We hope you enjoy our videos and educational content found throughout our site.

Contributors to our website are teachers and educators who care about you. They are constantly surrounded by English learners of a second language.

Audio files from Larisa English ClubAudio educational content is provided with resources from Larisa English Club contributors and English education partners. Many of our resources can be downloaded completely free of charge.

Look for content on our website that displays a special “Download Now” link. Our purpose for offering free educational content is to allow students the opportunity to study anytime, anywhere.

PDF files from Larisa English ClubPDF resources can be found throughout our site. English resources from beginner to advanced have been created by many educational providers.

Study English at a level you feel slightly challenged with and your English will improve daily. We encourage comments and suggestions at Larisa English

What is the best way to learn and remember English? Simple! Teach others. What do I mean by “Teach others?” That is simple to!

Learn English by teaching your friends and family what you have learned. Do it over and over, it will stay with you for a long time, maybe forever!

Study the areas of English that interest you the most. Surprisingly, you will learn other parts of English too.

All learners of a foreign language must remember that repetition is key to memorizing what you study. Studies have shown that it takes an English learner an average of seventeen interactions with specific elements to make that knowledge stick. In other words, after being exposed to a certain part of just about anything including English, you will most likely not forget soon.

What is the best method to study and learn great English? The truth is; There isn’t just one! Facts are facts. Everyone learns differently.

Some students like reading. Some like listening. Some like lecturing. It is all about you and what interests you. I can tell you from personal experience teaching English over nine years, no two people are the same.

That said, most successful learners of English, do it by teaching others first. The second best way might be when we speak to others. Group discussion is an important element to speaking.

Without practice and some challenges, students learn to speak fluently slower. If you want to speak great English, practice speaking with others.

Don’t forget, learning the basics in English should always come first for a second language. Speaking can also be incorporated in your English study at the earliest stages of your learning journey.

There is one great way to evaluate your English. It is simple called “Progress”. With progress you are moving ahead and towards new elements in English. If you have to relearn today what you learned yesterday, you have work to do.

The main idea is to make daily progress. If you are making daily progress, you are doing it right. For students who feel they are standing still with English, try something different.

It might be your study habits or one of many other factors. Just take a look at what you are doing everyday and just know that progress is the key to learning and speaking great English.

Once you have studied and learned the basics in English grammar, now it is time to practice, practice, practice. This is always a great idea with friends, family and colleagues.

They help you and you help others. Speaking fluency should be your number one goal. Proper pronunciation is also key to speaking understandably.

Some students and teachers believe that English can be studied and learned without grammar. This is simply not true. Many students are told this by teachers who don’t know grammar either.

This is very dangerous. Not knowing grammar before trying to use it in spoken English is always a bad idea. Once a student buys into this idea of speaking without grammar, he or she always forms nasty habits. Most of the time, these habits are impossible to break.

At some stage in your study of English, you will get to a point where you have a mountain of questions. This is often one of the last stages in English. This is when you need to work with an English teacher that can answer those questions.

This can only be done by someone who is qualified, confident and experienced. Never trust an unqualified person to teach you English or answer your questions.

Work with a qualified English teacher who will answer your questions accurately with confidence.

One important key to learning better and better English is continual exposure to the language. This can be a number of different ways but, do what is best for you. Is it music? What about watching your favorite sitcom? Does your spouse speak English?

Can you practice together? While there are many ways to learn just about anything, practice and being around others is one of the best methods of attaining English proficiency.

Once you feel confident that you have learned as much as needed to achieve your goals, now it is time for more vocabulary. Vocabulary along with speaking English is essential.

When you get to the Intermediate level of English, study new vocabulary daily. Look for three and four syllable words. As we climb that ladder of English proficiency, we need to speak and understand others.

Native speakers of English as well as advanced ESL students speak with words that might be more specific in meaning. To better understand others, you need vocabulary.

Remember, words are just words until you decide how to use them. Most nouns can be used as verbs while many verbs can also be used as nouns. A word is just a word until you decide what job to assign it.

The same goes for all words in English. Most people know the word “Yes” as an adverb. Did you know it is also a noun. Just like all words in English that follow the “Article” as a single word, it is a noun.

Verbs, Modifiers and Adjectives work the same way. To play the record (Noun) or to record (Verb) or to happen in a record time (Modifier). Another example might be the word “Live”. To live (Verb) in a country or to attend a live (Adjective) concert.

Remember that a word is just a word until you have decided how to use it in a statement. The usage and pronunciation might change.

What is the best way to study English? As mentioned before, there isn’t one. That said, for most people who study with a private tutor, progress is often faster. On-line lessons are another great way to study as well.

For those who like or need the interaction in a classroom with others, group study might be best. A professional private language school should offer, private, semi-private, mini-group and group lessons.

Remember that many schools refer to an hour of English as an academic hour. An academic hour of English is just 45 minutes. Professional private language schools always teach a full 60 (Sixty) minutes for each lesson.


What’s New?

The Antarctic is Turning Green
Larisa Article written by Billgreen54 ESL Tutor

The Antarctic is Turning Green

Ian Johnston Independent Environment Correspondent

Scientists say the frozen continent is likely to ‘alter rapidly under future warming, leading to major changes in the biology and landscape of this iconic region. The Antarctic is turning green with rising temperatures having a “dramatic effect” on the growth of moss in the frozen continent, scientists have discovered. Since 1950, temperatures in the Antarctic Peninsula have risen by about half a degree Celsius each decade. This is much faster than the global average.

The Antarctic

Growth rates of moss since 1950 have been running at four to five times the level before. This is according to a study by UK-based researchers who studied three sites across a 1,000km stretch of the peninsula. In addition to climate change, the extinction of animal species is prolific. Plastic waste, fossil fuel ash and radioactive particles from nuclear bomb tests will all leave a permanent record in the planet’s future rocks.

“Between 1950 and 2000, temperatures increased by half a degree per decade on average,” said Dr Amesbury of Exeter University. “The reason we are so confident the moss is responding primarily to temperature, is because of the wide-scale response we see in our moss banks from three different sites that stretch 1,000km across the Antarctic Peninsula.”

The researchers who reported the results of their study in an open-access paper in the journal “Cell Biology”, also looked into how sensitive the moss would be to further warming.

“The results of that analysis lead us to believe there will be a future ‘greening’ of the Antarctic and a further increase in moss growth rates. “We are likely to see massive amounts of moss colonizing new areas of ice-free land created by the warmer climate.

Read more here.

History Topic!

Land Discovery of The Antarctic in 1675

Thank you Wiki.

The first Antarctic land discovered was the island of South Georgia, visited by the English merchant Anthony de la Roché in 1675. Although myths and speculation about a Terra Australis (“Southern Land”) date back to antiquity, the first confirmed sighting of the continent of Antarctica is commonly accepted to have occurred in 1820 by a Russian expedition. The first human born in the Antarctic was Solveig Jacobsen. He was born on 8 October 1913 in South Georgia.

Scientists in the Antarctic

The Antarctic region had no indigenous population when first discovered. It’s present inhabitants comprise of just a few thousand transient scientific and other personnel. They work on tours of duty at several dozen research stations maintained by various countries. However, the region is visited by more than 40,000 tourists annually, the most popular destinations being the Antarctic Peninsula area (notably the South Shetland Islands) and South Georgia Island.

In December 2009, it was noted that the growth of tourism, brought along with it, consequences for both the ecology and the safety of the travelers in its great and remote wilderness. This was at a conference in New Zealand conducted by experts and signatories of the Antarctic Treaty. The definitive results of the New Zealand conference were presented at the Antarctic Treaty states’ meeting in Uruguay in May 2010.

Conversation Topic

Leading statements and questions

For learners of a second language, sometimes, dialog or conversation can be difficult.

For learners of a second language, sometimes, dialog or conversation can be difficult. Conversation engagement, is not that difficult with a few simple tricks. Asking a simple question to start out a conversation is easy with simple question words. I covered question words in a previous English Club.

Question words are often needed to carry on a conversation. The idea is to ask questions connected to details already mentioned. Try to do this while the other person is speaking. This is easy by visualizing objects and situations that are connected.

I call these “Leading Statements and Questions”. It is all about dialog and how to continue a conversation. Now, we go back to those questions words and how they connect. Here’s an idea and example. “What is your favorite food?”. An answer might be “My favorite food is pizza”. Now visualize in your thoughts “What kind of pizza do you like?”. Another question could be; “How often do you eat pizza?” or “Where do you eat pizza?” or “What is your favorite pizza?” or “Why is pizza your favorite?”

You can ask many questions with question words with leading questions and visual thoughts. Here! Take a look at a few examples with our speaking practice…

Speaking Practice

Creating Dialog with Leading Questions

Notice how I focus on the “Park” and “Connections” to the park along with other details relating to the park.

Larisa English Club Speaking PracticeDialogues

Leading questions are easy when you get the hang of it. Practice questions in English and keep the conversation going.

Basic Grammar Review

Prepositions of Place, Movement and Time

Classroom posters are another way for students to learn from and have a reference point when working with a teacher and fellow students.

English prepositions are always fun to learn. It helps if a teacher has classroom teaching aides to assist with examples. Classroom posters are another way for students to learn from and have a reference point when working with a teacher and fellow students.

English prepositions are all about place, movement and time. Before getting started with prepositions, there are two important words to teach as thoroughly as possible.

Start with the word “Arbitrary”. The word arbitrary is used when we refer to something when relevance is not exact. In this case, the word’s “something or anything are indefinite”.

The main objective here is to help students better understand that, when describing with prepositions, often there is more than one choice. In other words, examples like “Please sit near the table or by the table” have little difference in meaning. The main idea is to learn how to communicate. If we both understand what the other is saying; isn’t that perfect English? Or better yet! Perfect communication.

The second important word to learn is “Collocation”.

The second important word to learn is “Collocation”. Collocations or colloquial speech is when we use words in a certain order that are common in English. Commonly spoken word combinations are easier to understand than one might think. Collocations can be used many different ways in English. Common statements, phrasal verbs and the list goes on and on.

 One of the best ways to teach collocations and common word order is with a list of examples. This is done in order of importance. In other words, start by writing a simple statement with the most popular word combination or collocation. Examples might include, “Please have a seat at the table” or “Please have a seat by the table”.

Although these statements mean two different things, they are used universally. The main idea here is “Which word combination is used more commonly?”. Please sit “AT” the table is more common compared to; Please sit “BY” the table. Therefore “AT” is more common compared to “BY”.

Can we use both examples? Yes! Why? Because, I understand you!

Typical time expressions are all about colloquial speech. Place and movement prepositions are generally specific to places and movement but, many can be interchanged.

This is due to the difference between perfect grammar and spoken English. Again, it is often more important to communicate understandably, than to attempt to speak perfect English.

So, which prepositions are the ones we should start with and why teach prepositions in chunks? There are three to start with. Those would be “At, In, On”. These are the three most common prepositions. One of the best ways to learn prepositions is to connect them with understandable words. In other words; Vocabulary that you already know.

In English, there are many methods of teaching grammar. The main idea is to ask questions.

In English, there are many methods of teaching grammar. The main idea is to ask questions. Why do we use the word “AT?” “We use the word “AT” with locations or places”. Why do we use the word “IN?” “We use the word “IN” with limits”. Why do we use the word “ON?” “We use the word “ON” when two things touch”. These are common examples and general thoughts. There are exceptions to just about every rule in English. Just remember collocations and flexible English.

Choose other preposition words to chunk together and form common ways to describe identical situations. All students need to know that while all speech is important, the main goal should always be understandable communication. If an expression or statement is not perfect English but, the other fully understands your statement, isn’t that perfect English?

English Grammar

Reported Speech

A few simple thoughts about “Reported Speech”. There are two ways to report what happened or what someone said, “Direct Reported Speech” and “In-direct Reported Speech”.

Direct reported speech is used when we use the same tense when stated. In other words, if someone says “Hello”, we can refer to the statement with something like “He says hello!”. In this example, we use the same tense as what was said.

“Indirect reported speech” is when we refer to a statement or fact from the past and go back one tense in our statement. So, if someone said “I am hungry” we would say “He said he was hungry”. Notice how the verb “To be” changed from “Am to Was”. In this example, we went back one tense to refer to what was said.

Reported Speech

Another important element to “Reported Speech” is when we use “Modal Auxiliary Verbs”. In direct speech, we use the same modal verb used. In other words, if someone something like “I will go to work next week”, you report with the same modal verb. If you report with indirect speech, use “Would”. So, will to would, can to could, may to might and so on.

This is just a short explanation for reported speech. For more information regarding reported speech, look for grammar books at the Intermediate level and above.

Until next time…

I hope you enjoyed Larisa English Club number 5. Remember that “Life is an Adventure”. Live it to the fullest each and every day!


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