The Guinness World Records on Thursday declared 'Byakuya' made by Japanese ice cream brand Cellato as the world's most expensive ice cream, costing 873,400 Japanese yen (around ₹5.23 lakh) per serving. The ice cream is made with rare white truffles grown in Italy's Alba, which costs around ₹12 lakh/kg. Other special ingredients include Parmigiano Reggiano and sake lees.