the perfectly clear still apple and sparkling strawberry and kiwi contain malic acid, not citric acid.
i drink it every day and have made yummy lollies from the still apple. havent tried making into jellies though ( may have to try that)
as for the gelatine, i looked into the supercook gelatine and contacted supercook for the nutritional values. it is almost identical to the mix a mousse ( infact the mix a mousse needs one a a half scoops to make half litre jelly which is about 12 calories more than the supercook gelatine).
hope this helps