Yes, that's true. Venezuelans, compared to other latinamerican countries, are large consumers of ketchup. Apparently, some chavistas involved in the ketchup business wanted to get rid of Heinz ketchup so they might have pressed for this seizing. Some of Heinz's competitors in Venezuela:
Del Monte:
Pampero: (makers of Pampero Rum, supported Chavez's campaign back in '98)
Tiquire Flores brand, made by Empresas Polar (Venezuela's largest "private" company):
BTW, Heinz had to build this plant in order to supply the local market, as it is illegal to import more than $200 million in agricultural products from the US.
One the main reasons for the closure of this ketchup plant was that agriculture in Venezuela is very bad and farmer's productivity extremely low (the result of years of collectivization and protectionism) The farmers who supplied Heinz with tomatoes did not fulfill their supply agreement stating that tomatoes had to be sold at an agreed price and instead relinquish the contract and sold their tomatoes fresh to get a better price. Apparently they do not understand the words "agreed price" or "contract"
I remember two years ago when I was I Venezuela that I saw US-made Heinz ketchup being sold. It was of better taste, and anyone who could afford it bought it instead of the local made. This might have pushed the decision...