March 2017

Fruit juices and vegetable juices are very complex, consisting of hundreds of substances. They contain also essential vitamins and minerals as well as bioactive compounds that are known to have many health benefits. Although studies are fragmented and need to be expanded, particularly in the clinical area, juices may play a role in diseases related to chronic inflammation, cancer, heart and bone diseases, problems related to cognition and aging, and possibly insulin resistance. The mode of action of these fruit juice compounds in most cases seems to be by modulating gene activity. Fruit juices, consumed in moderation as part of a balanced diet, offer both: health and disease risk reduction properties. Furthermore, to identify moderate fruit juice consumption as inadvisable in the context of obesity and dental health, would deny the consumer a perfectly healthy and nutritious food, and be completely contrary to the totality of the current scientific evidence.

Fruits and juices are not drugs, and measurable health effects can be expected to be mild relative to the more dramatic outcomes expected with pharmacological medications. It can be proposed that the main role of fruit and fruit juices is a disease risk reduction.

September/Otober 2015

Following publication of the WHO guidelines for the consumption of sugars Fred Brouns (Maastricht University) challenges the conclusion that sugars in fruit juice should be considered as “added sugars”. The article was first published in September/October 2015 edition of fruit processing.

20/07/2015. Aschoff et al Mol. Nutr. Food Res. 2015. 59, 1896-1904

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Scope

Orange fruits and products thereof represent important dietary sources of carotenoids, particularly β-cryptoxanthin. Since previous studies reported a positive effect of vegetable processing on carotenoid absorption, our objective was to compare the bioavailability of β-cryptoxanthin from either fresh navel oranges (Citrus sinensis L. Osbeck) or pasteurized orange juice.

Conclusion

Orange juice represents a more bioavailable source of β-cryptoxanthin than fresh oranges.

08/01/2015. Aschoff et al J. Agric. Food Chem. 2015. 63. 578-587

Carotenoid, flavonoid, and vitamin C concentrations were determined in fresh orange segments and a puree-like homogenate derived thereof, as well as freshly squeezed, flash-pasteurized, and pasteurized juices. Lutein and β-cryptoxanthin were slightly degraded during dejuicing, whereas β-carotene levels were retained. Vitamin C levels remained unaffected, whereas flavonoid levels decreased 8-fold upon juice extraction, most likely due to the removal of flavonoid-rich albedo and juice vesicles. Likewise, the presence of such fibrous matrix compounds during in vitro digestion was assumed to significantly lower the total bioaccessibility (BA) of all carotenoids from fresh fruit segments (12%) as compared to juices (29–30%). Mechanical disruption of orange segments prior to digestion did not alter carotenoid BA, whereas pasteurization of the freshly squeezed juice slightly increased BA by 9–11%. In addition to carotenoid BA, the stabilities of hesperidin, narirutin, and vitamin C including dehydroascorbic acid during in vitro digestion were monitored, and applied analytical methods were briefly validated.

13/08/2015. Yannai et al,Cell Metabolism, Vol. 22, Issue 3, p531

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Highlights

•19 adults with obesity were confined to a metabolic ward for two 2-week periods

•Cutting carbohydrates increased net fat oxidation, but cutting fat by equal calories had no effect

•Cutting fat resulted in more body fat loss as measured by metabolic balance

•Mathematical model simulations predicted small long-term differences in body fat

Summary

Dietary carbohydrate restriction has been purported to cause endocrine adaptations that promote body fat loss more than dietary fat restriction. We selectively restricted dietary carbohydrate versus fat for 6 days following a 5-day baseline diet in 19 adults with obesity confined to a metabolic ward where they exercised daily. Subjects received both isocaloric diets in random order during each of two inpatient stays. Body fat loss was calculated as the difference between daily fat intake and net fat oxidation measured while residing in a metabolic chamber. Whereas carbohydrate restriction led to sustained increases in fat oxidation and loss of 53 ± 6 g/day of body fat, fat oxidation was unchanged by fat restriction, leading to 89 ± 6 g/day of fat loss, and was significantly greater than carbohydrate restriction (p = 0.002). Mathematical model simulations agreed with these data, but predicted that the body acts to minimize body fat differences with prolonged isocaloric diets varying in carbohydrate and fat.