Summary ASIA

For this project, an investigation was done looking into the piperine content in pepper for the Huijbregts Groep B.V (HG). Their products are involved in 80% of the daily meals in The Netherlands, due to their large role supplying colour, aroma and flavour additives for various food supplements. HG buys, blends and sells mostly food commodities in powder form, but also dried vegetables and spices. One of these dried products are peppercorns produced by the pepper plant (Piper Nigrum). The substance which gives these corns this spicy taste is piperine. HG is committed to make sure that their customers must be able to produce a consistent product without a perceivable taste difference between shipments.  For this reason, HG asked Fontys Hogescholen to produce a protocol whereby the piperine content can be measured and quantified.

              The pepper plant Piper Nigrum produces the peppercorns, the black, green and white corns are derived from this plant. The difference in colour has to do with the time of harvest, drying process and the after-treatment. De colour is not responsible for the spicy taste. Piperine is the main compound in these corns, it belongs to the chemical class called alkaloids. Due to this its poorly soluble in water, but good in organic solvents such as ethanol and methanol.

The set-up of this report is as follows; there are two extraction methods to be compared with each other, namely the Soxhlet and the reflux extraction. To determine the efficiency of the piperine content from these extractions, a calibration curve was compiled and measured with HPLC and UV/VIS spectroscopy. The HPLC was used to validate the UV/VIS method.

There are several practices implemented. The most reliable practice part is part 6, because there is used precise and analytical work. Therefore are the results based on part 6. The results showed us that the Soxhlet-extraction is the best method of extraction, because it is a continuous process without becoming saturated. And you have to perform less proceedings. To compare the Soxhlet and reflux extractions, the difference between de results of Soxhlet and reflux were very large. This difference can be explained as follows: the HPLC chromatogram has more than 2 or 3 peaks. The large peak is probably piperine. So, there is continued with the large peak. The UV/VIS measures all components in the sample. With the HPLC it is possible to choose the peak of interest, so the concentration could be calculated with these peak. The evaporate method didn’t gave the expected results. Probably there are more components extracted from the pepper. This can be seen in de FTIR spectrum of the sample. The spectrum has a great –OH peak at value 3200 cm^-1. The spectrum of pure piperine doesn’t have this great –OH peak.

From the Soxhlet-extraction there was concluded that the piperine content had an average of 6.1% measured with the UV/VIS. The piperine content measured with the HPLC for the Soxhlet-extraction had an average of 5.6%. From the reflux extraction there can be concluded that it has an average of 6.0% measured with the UV/VIS and an average of 5.5% measured with the HPLC.

With the chosen method it is possible to analyse and quanify the piperine content in pepper.

Week 6 exercises

Spot the errors

In each of the following sentences, there is one or more mistakes. Spot these errors and correct the sentences:


1. Could you please send me an oversight of the conferenceprogramme? 

overview
2. Unfortunately, he refused talking to me. 

He refused to talk to me
3. Thanks for caring, but I'm fine. There is nothing on the hand. 

There is nothing going on
4. I'd like to congratulate you with your birthday. 

On your birthday
5.Thank you for showing interest in our company. We will get back at you as soon as possible.

Come back to
6. House prices have increased with 3.1% this year. 

With = By
7. I'll send you an answer on your question by Monday at the latest. 

on = to
8.According an actual publication, women drink more coffee than men. 

According to
9. My best friend is someone who appears to have only good qualities.
She is kind, generous, caring, self-absorbed. In short, she's just a wonderful person. 

shortly
10. I'm looking forward at the weekend very much. 

at = to

Hedging - answers

Exercise 1

Identify the hedging expressions in the following sentences.

1. There is no difficulty in explaining how a structure such as an eye or a feather contributes to survival and reproduction; the difficulty is in thinking of a series of steps by which it could have arisen.
2. For example, it is possible to see see that in January this person weighed 60.8 kg for eight days,
3. For example, it may be necessary for the spider to leave the branch on which it is standing, climb up the stem, and walk out along another branch.
4. Escherichia coli , when found in conjunction with urethritis, often indicate infection higher in the uro-genital tract.
5. There is experimental work to show that a week or ten days may not be long enough and a fortnight to three weeks is probably the best theoretical period.
6. Conceivably, different forms, changing at different rates and showing contrasting combinations of characteristics, were present in different areas.
7. One possibility is that generalized latent inhibition is likely to be weaker than that produced by pre-exposure to the CS itself and thus is more likely to be susceptible to the effect of the long interval.
8. For our present purpose, it is useful to distinguish two kinds of chemical reaction, according to whether the reaction releases energy or requires it.
9. It appears to establish three categories: the first contains wordings generally agreed to be acceptable, the second wordings which appear to have been at some time problematic but are now acceptable, and the third wordings which remain inadmissible.

Prepositions commonly used in academic writing

Use a dictionary and fill in the correct prespositions which match the following nouns:

an alternative for
an improvement over
a reaction to
a shift for/in
associate with
compatible  with

consistent with

derive from

devoted with

deviation from

exclude from

in comparison with
in contrast to

in line for

in spite of

 in terms with
in average
with behalf of
for the whole
with the exception of
to be aware of
to comment for
to distinguish from
to engage with

Summary 2

Summary 2

In this article  “Enzymatic-spectrophotometric determination of sucrose in coffee beans”, A. Alcazar, J. Marcos Judaro, A. Gustavo Gonzalez (2005) wrote a report about determining sucrose in samples of coffee beans with an enzymatic spectrophotometric.

Coffee flavour is developed during the roasting process of beans. Sucrose is a very important flavour. Sucrose is the major free sugar present in green coffee. It has been quantitated in coffee beans by using ion chromatography. The ion chromatography separation looks very easy. However, the detection presents several handicaps. The determination of low molecular weight sugars, specially sucrose, can be easily carried out by using enzymatic procedures. In this case the author used selectivity from the features of the enzymatic process, leading to the quantitation of sucrose without interferences from other glucides. So the aim of the paper is to develop an enzymatic spectrophotometric method for determining sucrose in samples of coffee beans.

For this experiment an Unicam UV series 500 with quartz-cells of 1.0 cm was used. The green coffee samples were supplied from Centre National de Recherche Agronomique (CNRA). Roasted coffee samples were obtained from local stores. Before starting, the samples were sieved and dried.

In order to evaluate the applicability of the method, samples of green and roasted coffee were analysed. Since the method is based on glucose released by invertase activity the author considered possible interferences due to the presence of endogenously reducing sugars. The sugars are present in green coffee, but the quantities are very small. In the green coffee values between 7.6 and 4.6% were obtained. These results are in accord with the reported values in Ref.  In the case of the roasted coffee, no sucrose was found. Sucrose is lost rapidly during roasting process, so that at a medium or dark type of roast sucrose is completely lost.

As a conclusion, the proposed method has been shown to be useful for determining sucrose in coffee beans. The experiment is suitable, easy to apply and does not need expensive instrumentation. The most important variable was the temperature of the extraction step.  No differences have been found between the proposed method and the currently practiced method.

Week 4 common errors and paragraphing

Common errors

-          Specially/especially

-          That/which

-          Use/usage

-          Were/where

-          Shall/will

-          May/might

-          Less/ fewer

-          If/whether 

Introduction

Patulin is produced by various molds, which primarily infect the moldy part of apples. Removing the moldy and damaged parts of the fruit may not eliminate all the patulin because some of it may

migrate into sound parts of the flesh. Also, patulin can be produced within the fruit, even though it may not be visibly moldy. If moldy apples are used to produce apple juice, the patulin goes into the juice. It is not destroyed by heat treatments such as the pasteurization process. Patulin is a natural human toxin and therefore can have genetic affects within cells, including a developing fetus, the immune system and the nervous system. The recommended advisory level is 50 μg of patulin/kg in apple juice [50 parts

per billion (ppb)].1 Hydroxymethylfurfural (HMF), also 5-(Hydroxymethyl)furfural, is an organic compound derived from dehydration of sugars. HMF has been identified in a wide variety of heat-processed foods including milk, fruit juices, spirits, honey, etc.2

Topic sentence
Patulin is… of apples.	Subtopic 1 Removing the .. the flesh.	Example X1 a Also, patulin.. visibly moldy.
	Subtopic 2 Patulin is … human toxin	Example X2 a Therefore..nervous system.