When Puan Noor Aishah moved into the Istana in 1959, she changed the way the staff ran the former British governor's home and introduced local touches.
One of the changes that Madam Noor Aishah - the widow of Singapore's first Yang di-Pertuan Negara and later president Yusof Ishak - made was to the menu.
Instead of English food like roast beef and Yorkshire pudding, the then 25-year-old trained the cooks to master dishes that reflect the local palate, such as beef rendang, gula melaka dessert and chap chye.
In doing so, she brought a local flavour to the former colonial residence, where state ceremonies are held.
Her story is among the many captured in a coffee-table book launched yesterday. Commissioned by President Tony Tan Keng Yam, Our Istana - Through The Years contains montages of photographs and stories from people who have passed through the Istana's gates.
Yesterday, Madam Noor Aishah, 81, displayed her knowledge of spices as she, in a tour of the Istana gardens with other guests, pointed out how ingredients such as nutmeg enhance the flavour of kueh lapis.
"We had two chefs who were used to cooking English food. I told them to use more spices, so they could cook Asian food such as sambal and rendang," she told The Straits Times.
"When I was here, there was no garden, but today the Istana has many beautiful plants."
Her stay at the Istana ended in 1970, when her husband died.
Besides Madam Noor Aishah, other Singaporeans such as former defence chief Winston Choo were interviewed for the book.
Mr Choo, now 74, was a young major when he became Singapore's first full-time aide-de-camp to the president in 1965.
He said: "Encik Yusof was a wonderful man to work for - understanding, though demanding. I was engaged at that time. During the interview, he told me, 'If I choose you, you must postpone your wedding.' He chose me, and it was a wonderful two years working here, though my wife may not agree."
The learning curve was steep, he added. "One of the things we had to figure out was how to receive ambassadors. The British protocol was to send a horse and carriage, but we did not have that. So we used a Mercedes car. We adapted - it is the Singapore way."
Speaking at the book launch, President Tan said he was struck by the stories and photos that gave an insight of not just the changes that took place in the Istana, but also how its evolution reflected Singapore's development in various fields, such as foreign relations, community development, the arts and sports.
"The Istana is not just a heritage building or an institution, but an important part of our shared history and identity," he said.
The book features photos from the National Archives of Singapore and Singapore Press Holdings (SPH), as well as from professionals and hobbyists.
Those interested can download the book for free at the Istana website, or buy a hard copy at $50 by sending an e-mail to email@example.com. Proceeds will go to the President's Challenge Silver Volunteer Fund for the pioneer generation.
Copies of a limited edition of the book, with President Tan's signature, are available at $10,000 each. Singaporeans can share their memories of the Istana by using the hashtag #ouristana on Instagram.