Abstract
The pre-thermal treatment, or blanching, is an important process to minimize quality changes during main cooking or storage. In this study, three types of pre-thermal treatments were applied to onions to observe quality changes in their physicochemical, nutritional, and microbial properties. The washed and sliced onions were treated by hot-water immersion (100°C, 1~10 min), steaming (100°C, 1~10 min) and stir-frying with oil (180°C, 10~80 sec). The onions were cooled and wiped with gauze. The results showed that the total color difference of the treated sample increased to 18-23 units compared to that of the fresh control. The pH value of the onion was not significantly different with the exception of the stir-fried samples. The hardness of the onion tended to decrease depending on the treatment time. The micro-structures of onions treated by hot-water immersion and steaming were damaged above 2 min whereas stir-fried onions showed structural damage above 210 sec. In the analysis of the nutritional changes in the onion, the ascorbic acid content of the blanched treatments were lower than that of fresh onion and the free sugar contests showed a similar pattern excluding the stir-fried onions. In the organic acid content assay, the succinic acid content of the treated onion sample had significantly decreased compared with other organic acid contents (p<0.05). The peroxidase activities of the blanched treatments by hot-water immersion and steaming were inactivated by more than 92%, whereas only 76% inactivity was achieved by the stir-frying treatment. The mesophilic and psychrotrophic bacteria counts of the treated onion were not detected or decreased to near a 3-log scale, and yeast was detected only the sample treated by the stir-frying for 1 min. In particular, neither bacteria nor yeast counts in all onion samples by steam treatment were detected. Consequently, the results demonstrated that steam treatment for 2 min could be the optimal pre-thermal condition for onions to minimize the quality changes and increase safety.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 16
Claim · model-written summary
Pretreatment increased onion color difference to 18-23 units against fresh control.
- Taxon
- Onions
Allium cepat0 - Treatment
- treated samplee0
- Outcome
- total color differencee0
- Direction
- increasede0
- Value
- 18-23 unitse0
- Comparator
- fresh controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“total color difference of the treated sample increased to 18-23 units compared to that of the fresh control”
t0“Onions”
Claim · model-written summary
Onion pH did not differ significantly except in stir-fried samples.
- Taxon
- onionAllium cepae0
- Treatment
- stir-fried samplese0
- Outcome
- pH valuee0
- Direction
- not significantly differente0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The pH value of the onion was not significantly different with the exception of the stir-fried samples”
Claim · model-written summary
Onion hardness tended to decrease with treatment time.
- Taxon
- onionAllium cepae0
- Treatment
- treatment timee0
- Outcome
- hardnesse0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The hardness of the onion tended to decrease depending on the treatment time”
Claim · model-written summary
Hot-water immersion damaged onion micro-structures above 2 min.
- Taxon
- onionsAllium cepae0
- Treatment
- hot-water immersione0
- Outcome
- micro-structurese0
- Qualifier
- above 2 mine0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“micro-structures of onions treated by hot-water immersion and steaming were damaged above 2 min”
Claim · model-written summary
Steaming damaged onion micro-structures above 2 min.
- Taxon
- onionsAllium cepae0
- Treatment
- steaminge0
- Outcome
- micro-structurese0
- Qualifier
- above 2 mine0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“micro-structures of onions treated by hot-water immersion and steaming were damaged above 2 min”
Claim · model-written summary
Stir-frying damaged onion structure above 210 sec.
- Taxon
- onionsAllium cepae0
- Treatment
- stir-friede0
- Outcome
- structural damagee0
- Qualifier
- above 210 sece0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“stir-fried onions showed structural damage above 210 sec”
Claim · model-written summary
Blanched onion had lower ascorbic acid content than fresh onion.
- Taxon
- onionAllium cepae0
- Treatment
- blanched treatmentse0
- Outcome
- ascorbic acid contente0
- Direction
- lowere0
- Comparator
- fresh onione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ascorbic acid content of the blanched treatments were lower than that of fresh onion”
Claim · model-written summary
Blanched onion had lower free sugar content than fresh onion except for stir-fried onion.
- Taxon
- onionAllium cepae1
- Treatment
- blanched treatmentse1
- Outcome
- free sugar contestse0
- Qualifier
- excluding the stir-fried onionse0
- Comparator
- fresh onione1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“free sugar contests showed a similar pattern excluding the stir-fried onions”
e1“ascorbic acid content of the blanched treatments were lower than that of fresh onion”
Claim · model-written summary
Treated onion succinic acid content decreased significantly compared with other organic acids.
- Taxon
- onionAllium cepae0
- Treatment
- treated onion samplee0
- Outcome
- succinic acid contente0
- Direction
- decreasede0
- Value
- p<0.05e0
- Comparator
- other organic acid contentse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“succinic acid content of the treated onion sample had significantly decreased compared with other organic acid contents (p<0.05)”
Claim · model-written summary
Hot-water blanching inactivated onion peroxidase by more than 92%.
- Taxon
- OnionsAllium cepat0
- Treatment
- hot-water immersione0
- Outcome
- peroxidase activitiese0
- Direction
- inactivatede0
- Value
- more than 92%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“peroxidase activities of the blanched treatments by hot-water immersion and steaming were inactivated by more than 92%”
t0“Onions”
Claim · model-written summary
Steam blanching inactivated onion peroxidase by more than 92%.
- Taxon
- OnionsAllium cepat0
- Treatment
- steaminge0
- Outcome
- peroxidase activitiese0
- Direction
- inactivatede0
- Value
- more than 92%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“peroxidase activities of the blanched treatments by hot-water immersion and steaming were inactivated by more than 92%”
t0“Onions”
Claim · model-written summary
Stir-frying inactivated onion peroxidase by 76%.
- Taxon
- OnionsAllium cepat0
- Treatment
- stir-frying treatmente0
- Outcome
- inactivitye0
- Value
- 76%e0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“only 76% inactivity was achieved by the stir-frying treatment”
t0“Onions”
Claim · model-written summary
Treated onion mesophilic and psychrotrophic bacteria counts were undetected or fell to near 3-log.
- Taxon
- onionAllium cepae0
- Treatment
- treated onione0
- Outcome
- mesophilic and psychrotrophic bacteria countse0
- Direction
- decreasede0
- Value
- 3-log scalee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“mesophilic and psychrotrophic bacteria counts of the treated onion were not detected or decreased to near a 3-log scale”
Claim · model-written summary
Yeast was detected only after one minute of onion stir-frying.
- Taxon
- OnionsAllium cepat0
- Treatment
- stir-frying for 1 mine0
- Outcome
- yeast was detectede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yeast was detected only the sample treated by the stir-frying for 1 min”
t0“Onions”
Claim · model-written summary
Steam-treated onion samples had no detected bacterial or yeast counts.
- Taxon
- onionAllium cepae0
- Treatment
- steam treatmente0
- Outcome
- neither bacteria nor yeast countse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“neither bacteria nor yeast counts in all onion samples by steam treatment were detected”
Claim · model-written summary
The authors identified two minutes of steam treatment as optimal for onion quality and safety.
- Taxon
- onionsAllium cepae0
- Outcome
- steam treatment for 2 mine0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“steam treatment for 2 min could be the optimal pre-thermal condition for onions to minimize the quality changes and increase safety”
The same questions in other papers
application · physiology: antioxidant enzymes · Allium cepa (onion)Positive and negative results
2 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
processing · quality: phytochemicals · Allium cepa (onion)Positive and negative results
6 papers in the same direction as this paper · 12 in the opposite direction
- positive
- positive
- positive
15 papers more in this group
See all 19 papers →processing · physiology: antioxidant enzymes · Allium cepa (onion)Results agree
1 paper in the same direction as this paper
- positive
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.