ORIGINAL_ARTICLE
Effect of Roasting on Physicochemical Properties of Cocoa Beans
Cocoa beans (Theorem cocoa) are the main raw materials used in chocolate manufacture. Roasting is the mostimportant technological process in production of cocoa products. It is the main process in the development of aromaand taste of cocoa beans. Maillard reaction and Strekher degradation take place during roasting process, where theflavour compounds of cocoa are produced. It was found that roasting temperatures at a range from 90 to 110°C wereoptimum for producing high quality chocolate, by using the Response Surface Methodology (RSM). The desirableflavour components of cocoa beans are developed due to the pyrazines which are produced during roasting process.This process affects the chemical composition (protein, fat, carbohydrates, ash, minerals and vitamins) of cocoa beans.The stability of polyphenols in cocoa beans is influenced by the conditions of the roasting process. Roasting causesa decrease in the polyphenols content of cocoa beans up to 98%. The roasting process of cocoa beans should be optimized(temperature and time) to produce final products of high quality.
https://ajfs.journals.ekb.eg/article_71652_6e6d30f204e21951f4786165d327a9d7.pdf
2019-12-01
1
7
10.21608/ajfs.2019.14658.1012
Cocoa beans
roasting
flavour
pyrazines
chocolate
mohamed
youssef
m_m_youssef@yahoo.com
1
Food Science and Technology Faculty of Agriculture - Alexandria University
LEAD_AUTHOR
ORIGINAL_ARTICLE
Reducing the Soluble Oxalate and Phytic Acid in Taro Corm Chips by Soaking in Calcium Salt Solutions
Taro (Colocasia esculentum (L)) corm is one of the most nutritious and easily digested foods, but unfortunatelycontains anti-nutritional factors such as oxalates and phytic acid .The oxalates which can lead to risks of kidneystones, while phytic acid reduces bioavailability of minerals. Therefore, the anti-nutritional factors must be removedor decreased before utilization of corm as food by carrying out chemical or physical process such as soaking, boiling,fermentation or cooking. So, the incorporation of chemical and physical methods is expected to be a very efficient waysof processing. The aim of the present study was to investigate the effect of using calcium salts such as calcium carbonate,calcium chloride and calcium sulphate at different concentrations (0, 1, 3, 5 % w/v) during soaking periods for (30and 60 min) on reducing soluble oxalate and phytic acid in taro corm chips. The experimental results indicated that theoptimal conditions were soaking taro corm chips in calcium chloride solution at concentration of 5% for 60 min., sincethe content of both soluble oxalate and phytic acid were found to decrease from 294.3 to 35.1 mg/100g and from 161.16to 133.68 mg/100g respectively. Calcium carbonate was the lowest effective additive.
https://ajfs.journals.ekb.eg/article_71656_70fd9b1f83eedfbbfe821f738bf4724c.pdf
2019-12-01
9
16
10.21608/ajfs.2019.20766.1015
Taro corm chips
soluble oxalate
phytic acid
calcium salts
pH
samaa
saleh
samaa8mhs@yahoo.com
1
Food Science Department, Faculty of Agriculture (Saba Basha), Alexandria University, Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
Conversion of inorganic selenium to organic form(s) by Lactobacillus acidophilus
The bioconversion of 2 forms of inorganic selenium namely selenite (SeIV) and selenate (SeVI) to organicform(s) by Lactobacillus acidophilus strain was investigated. The cultured media (MRS) was supplemented with 1,2, 5, 10, 20 ppm of Se in the form of sodium selenite (Na2SeO3, SeIV) or sodium selenate (Na2SeO4, SeVI) and incubatedat 37°C up to 24 hr Both Se forms showed no marked effect on the bacterial growth indicating no cytotoxicityat these concentrations. However, the media supplemented with 5, 10 and 20 ppm of Se(IV), but not Se(VI), becamereddish after 24 hr of incubation with increasing the red color intense with increasing the Se content in the media. Thescanning electron microscope (SEM) investigation clarified the presence of Se-nano particles (SeNPs) in the media.Se speciation of the cultured media supernatant and its corresponding cell fractions using HPLC-ICP-MS techniqueindicated that the bioconversion rate of Se to organic form(s) was extremely higher in Se(IV) than Se(VI) in both fractionshowever, the cell fractions contained the highest content. The organic Se gradually increased in both fractionswith increasing the media Se content. The inorganic Se was completely bio-converted to organic form(s) without anyresidual only in the medium contained 1 ppm Se(IV). Our results demonstrate the ability of L. acidophilus to convertSe(IV) but not Se(VI), at a limit concentration of 1 ppm and accumulate organic Se form(s) in the cell fraction. Theseresults confirm the possible bio-production of organic Se enriched fermented dairy products.
https://ajfs.journals.ekb.eg/article_71648_76d026e63a139fe2facfefc359d8ff45.pdf
2019-12-01
17
24
10.21608/ajfs.2019.12751.1011
bioremediation
organic selenium
inorganic selenium
L. acidophilus
nanoselenium
Mohsen
Zommara
mzommara@agr.kfs.edu.eg
1
Department of Dairy Science, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, Egypt
LEAD_AUTHOR
József
Prokisch
jprokisch@agr.unideb.hu
2
University of Debrecen, Faculty of Agricultural and Food Sciences and Environmental Management Institute of Animal Science, Biotechnology and Nature Conservation, Nanofood Laboratory, Debrecen, Hungary
AUTHOR
ORIGINAL_ARTICLE
Prevalence and antibiotic resistance of Staphylococcus aureus isolated from raw milk and dairy products collected from Alexandria, Egypt
The aim of the present study was to determine the prevalence and antibiotic susceptibility of Staphylococcusaureus (S. aureus) isolated from raw milk and some dairy products collected from shops, grocery stores, street vendorsat different markets in Alexandria, Egypt and identification of the genes responsible for resistance to some importantantibiotics using polymerase chain reaction (PCR) technique. The results of the raw milk and dairy productsexamined, 22.5% of the samples were positive for S. aureus. It was isolated from 29% of raw milk samples, 12.5%of Kariesh cheese samples, 55% of White cheese samples, 10% of Ras cheese samples, 5.7% of yoghurt samples and24.3% of cream samples. Antimicrobial susceptibility test revealed that all the isolates were susceptible to ciprofloxacin,co-trimoxazole, linezolid, rifampin and vancomycin. Resistance to penicillin G, tetracycline, cefoxitin, chloramphenicol,erythromycin and gentamycin were detected in 91.4%, 65.4%, 42%, 13.6%, 12.3% and 9.9% of the isolates,respectively. The mecA resistance gene was identified in 91.2% of cefoxitin resistant S. aureus isolates, aacA-D wasdetected in 87.5% gentamycin resistant isolates and ermC gene was detected in 100% of S. aureus isolates showedmacrolides resistance whereas ermA could not detected in any of them. The overall prevalence of methicillin resistantS. aureus )MRSA( in the tested raw milk and dairy product samples was 8.6%. The highest methicillin resistant S.aureus prevalence was reported in white cheese samples of 22.5% followed by raw milk, Ras cheese, cream, yoghurtand Kariesh cheese with prevalence of 11%, 7.5% 7.14% 2.9% and 2.5%, respectively
https://ajfs.journals.ekb.eg/article_71655_1d47d5ef23d6f669cd14d762cc3d36a3.pdf
2019-12-01
25
33
10.21608/ajfs.2020.15880.1014
Staphylococcus aureus
Dairy products
prevalence
Antibiotic resistance
Sahar
Abd El Halem
sahar.gamal500@gmail.com
1
Dairy scince and technolongy department
LEAD_AUTHOR
ORIGINAL_ARTICLE
IMPROVEMENT PHESIO-CHEMICAL SENSORY AND MICROBIOLOGICAL CHARACTERS OF SWEET SORGHUM
The present work was carried out to evaluate four types of sweet sorghum syrup made from Mn 4080 sweet sorghumvariety either alone or with one of three herbal extracts (tumeric, cinnamon and ginger) for the physicochemical,sensory and microbiological properties.The results indicated that sweet sorghum syrup contained cinnamon extract had the highest percentages of sugarprofile, tannins, total phenolics, antioxidant activity and minerals (K, Ca and Fe). Moreover, purity and the degree ofbrowning and darkening were increased. Organoleptically, syrup contained cinnamon extract had the highest scorein the overall acceptance as compared with the other sorghum syrup types. The results also showed that extracts cinnamonherb played a good role in shelf-life stability during storage period at 25 ± 2°C up to 9 months.The present work suggests that the cinnamon extracts can be used as an antioxidant and to improve the palatabilityof sorghum syrup.
https://ajfs.journals.ekb.eg/article_71640_86e37294fe9675d4bb4e064970e94b13.pdf
2019-12-01
35
43
10.21608/ajfs.2020.14239.1010
sweet sorghum syrup
herbs flavor
physico-chemical
sensory
microbial counts
soha
khalil
sohakhalilscri@gmail.com
1
sugar crops research institute., dept sugar technology
LEAD_AUTHOR
samer
helmy
allabbodyashraf@yahoo.com
2
Sugar Technol., Res. Dept., Sugar Crops Res. Inst., Agric. Res. Center, Giza, Egypt
AUTHOR
anwar
sasy
anwarsasy66@gmail.com
3
Sugar Technol., Res. Dept., Sugar Crops Res. Inst., Agric. Res. Center, Giza, Egypt
AUTHOR