Effect of Soluble Solids and Temperature on Ascorbic Acid Degradation in Lemon Juice Stored in Glass Bottles

Robertson, Gordon L.; Samaniego-Esguerra, Christine M.

doi:10.1111/j.1745-4557.1990.tb00032.x

Cited by 15 publications

(2 citation statements)

References 24 publications

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“…Degradation may also occur, especially of ascorbic acid, as a consequence of heat-treatment and storage [98,99]. Such phenomena have been investigated by a number of researchers [100][101][102][103][104]. The main factors affecting ascorbic acid loss in orange juice during processing include temperature, salt and sugar concentration, pH, oxygen, enzymes, light, metal catalysts, and initial ascorbic acid concentration [105].…”

Section: Influence Of Citrus Processing On Vitamin C Contentmentioning

confidence: 99%

Vitamin C and the Role of Citrus Juices as Functional Food

Martí

Mena

Cánovas

et al. 2009

Natural Product Communications

112

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The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Non-thermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life. The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined. Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H 2 O 2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C. Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.

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Section: Influence Of Citrus Processing On Vitamin C Contentmentioning

confidence: 99%

Vitamin C and the Role of Citrus Juices as Functional Food

Martí

Mena

Cánovas

et al. 2009

Natural Product Communications

112

View full text Add to dashboard Cite

show abstract

“…Degradation of Vit C proceeds by both aerobic and anaerobic pathways [7] and depends upon many factors such as oxygen, heat, light, storage temperature and storage time [8] and also during cooking. Factors that affect the Vit C contents of citrus fruits include, production factors, climate conditions, maturity state and position on the tree, type of fruits (species and variety), type of container, handling and storage [9,10].…”

Section: Introductionmentioning

confidence: 99%